Acts 2

Translator Notes

1. The Greek symplērousthai ('to be fulfilled, to arrive in fullness') suggests not merely that the day came but that it reached its appointed fullness — a theologically loaded term. Pentecost (pentēkostē, 'fiftieth') fell fifty days after Passover. As a harvest festival (Shavuot), it was one of three pilgrimage feasts requiring attendance in Jerusalem, explaining the international crowd described in verses 5-11.
2. The phrase epi to auto ('in one place' or 'together') echoes 1:15 and emphasizes the unity of the community at the moment of the Spirit's descent.

Translator Notes

1. The Greek pnoē ('wind, breath, blast') is related to pneuma ('spirit/wind') — the wordplay connects the physical phenomenon to the Holy Spirit (pneuma hagion). The wind comes 'from heaven' (ek tou ouranou), marking its divine origin. The verb eplērōsen ('filled') anticipates the believers being 'filled' with the Spirit in verse 4. The violence of the wind (biaias, 'forceful, violent') recalls the theophany at Sinai (Exodus 19:16-19) and Elijah's experience at Horeb (1 Kings 19:11).
2. [TCR Cross-Reference] Draws on Exodus 19:16-19. Consult the TCR rendering of that passage for the underlying Hebrew and the rationale for key translation choices.
3. [TCR Cross-Reference] Draws on 1 Kings 19:11. Consult the TCR rendering of that passage for the underlying Hebrew and the rationale for key translation choices.

Translator Notes

1. The Greek diamerizomenai ('distributing themselves, dividing') describes the fire separating into individual flames — one for each person. The word glōssai ('tongues') does double duty: the fire appears in tongue-like shapes, and the result is speaking in tongues (languages). Fire is a consistent symbol of divine presence in the Old Testament: the burning bush (Exodus 3:2), the pillar of fire (Exodus 13:21), and the fire on Sinai (Exodus 19:18). That the fire rests on 'each one' (hena hekaston) emphasizes the individual, personal nature of the Spirit's coming — not corporate only but personal.
2. [TCR Cross-Reference] References Exodus 3:2 — the TCR OT rendering of that text provides the Hebrew source and explains the translation decisions involved.
3. [TCR Cross-Reference] References Exodus 13:21 — the TCR OT rendering of that text provides the Hebrew source and explains the translation decisions involved.
4. [TCR Cross-Reference] References Exodus 19:18 — the TCR OT rendering of that text provides the Hebrew source and explains the translation decisions involved.

Key Terms

Translator Notes

1. The passive eplēsthēsan ('were filled') indicates divine action — the Spirit fills them; they do not generate the experience themselves. The phrase heterais glōssais ('other tongues/languages') is clarified by verses 6-11 as known human languages, not ecstatic speech. The verb apophthengesthai ('to speak out, to declare boldly') is rare in the New Testament (used only here, v. 14, and 26:25) and carries the connotation of inspired, prophetic utterance — weighty proclamation, not babbling.

Translator Notes

1. The phrase 'from every nation under heaven' (apo pantos ethnous tōn hypo ton ouranon) is hyperbolic but reflects the reality that the Jewish diaspora extended throughout the Roman Empire and beyond. These are not tourists but katoikountes ('residing, dwelling') — diaspora Jews who had settled in Jerusalem, likely for religious reasons. The word eulabeis ('devout, reverent, God-fearing') characterizes them as pious Jews, not yet Christians.

Translator Notes

1. The 'sound' (phōnēs) likely refers to the sound of the wind from verse 2 rather than the speaking in tongues. The verb synechythē ('was bewildered, confounded, thrown into confusion') is a strong word indicating deep cognitive dissonance — they cannot make sense of what they are experiencing. The phrase tē idia dialektō ('in his own dialect/language') specifies that this is not generic babbling but precise, recognizable languages corresponding to each listener's mother tongue.

Translator Notes

1. The double expression existanto kai ethaumazon ('were astonished and amazed') piles up terms for shock. Galileans were known for their distinctive accent (cf. Matthew 26:73) and were generally regarded by Judeans as less educated and culturally unsophisticated. The rhetorical question highlights the incongruity: how can these provincial Galileans speak fluently in the sophisticated languages of the wider world?

Translator Notes

1. The phrase 'in which we were born' (en hē egennēthēmen) specifies these as mother tongues — the languages heard in childhood, the deepest linguistic identity. This detail rules out the interpretation that the audience merely understood a common language like Aramaic or Greek; they each heard their own distinct dialect.

Translator Notes

1. The list begins with regions east of the Roman Empire (Parthia, Media, Elam — modern Iran and Iraq) and moves westward. This geographical sweep represents the entire known world. The inclusion of 'Judea' is surprising in a Jerusalem setting — some scholars emend it to 'Armenia' or 'India,' but the text may simply mean Jews from the Judean countryside as opposed to Jerusalem residents, or it may represent the complete geographical coverage Luke intends.

Translator Notes

1. The list continues through Asia Minor (Phrygia, Pamphylia), North Africa (Egypt, Libya/Cyrene), and reaches Rome itself. The 'visitors from Rome' (hoi epidēmountes Rhōmaioi) are temporary residents or pilgrims, distinguished from the permanent Jerusalem settlers of verse 5. Cyrene in Libya had a large Jewish community; Simon of Cyrene who carried Jesus's cross came from there (Luke 23:26).

Translator Notes

1. The phrase 'Jews and converts' (Ioudaioi te kai prosēlytoi) is a parenthetical clarification covering the entire list — all these nationalities include both ethnic Jews and Gentile converts to Judaism. The content of the Spirit-enabled speech is 'the mighty deeds of God' (ta megaleia tou theou) — not random utterances but coherent praise of God's great acts. This echoes the Hebrew magnalia Dei tradition found in the Psalms.
2. The list ends with Cretans (island Mediterranean) and Arabs (the desert south and east), completing the compass-point coverage of the known world.

Translator Notes

1. The verb diēporoun ('were perplexed, were at a loss') indicates genuine intellectual struggle, not dismissal. These are devout people trying to make sense of an unprecedented event. The question 'What does this mean?' (ti thelei touto einai, literally 'What does this wish to be?') sets up Peter's sermon, which will provide the scriptural interpretation.

Translator Notes

1. The verb diachleuazontes ('mocking, jeering, sneering') is intensified by the prefix dia-, indicating thorough mockery. Gleukos ('sweet wine, new wine') was unfermented or partially fermented grape juice — lower in alcohol than aged wine. The accusation is somewhat absurd: it would take large quantities of sweet wine to produce drunkenness, especially in the morning. Peter addresses this directly in verse 15.

Translator Notes

1. Peter stands 'with the eleven' (syn tois hendeka), showing apostolic solidarity — he speaks as their representative, not as an individual. The verb apephthenxato ('spoke out, declared') is the same rare verb used in verse 4 for Spirit-inspired speech, linking Peter's sermon to the same Spirit-empowerment that produced the tongues. The phrase enōtisasthe ('give ear, listen carefully') is a Septuagintalism echoing the prophetic call to attention (cf. Isaiah 1:2).
2. [TCR Cross-Reference] Echoes Isaiah 1:2. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. The 'third hour' (hōra tritē) is approximately 9:00 AM by Jewish time reckoning (counting from sunrise at roughly 6:00 AM). Peter's argument from the time of day is practical: even on feast days, people did not drink before the morning prayers and sacrifices were complete. The defense is simple but effective — and it is merely the setup for the real explanation that follows.

Translator Notes

1. Peter identifies the Pentecost event as the fulfillment of Joel's prophecy — 'this is that' (touto estin to) is a direct identification formula. The preposition dia ('through') presents Joel as the instrument through whom God spoke, consistent with the view of prophetic inspiration expressed in 1:16.

Translator Notes

1. Peter's quotation modifies Joel 2:28 (LXX 3:1) in a significant way: Joel has 'after these things' (meta tauta), but Peter substitutes 'in the last days' (en tais eschatais hēmerais), explicitly interpreting Pentecost as the inauguration of the eschatological age. The pouring out of the Spirit is universal in scope — 'all flesh' (pasan sarka) breaks barriers of gender (sons and daughters), age (young and old), and as verse 18 will add, social status.
2. [TCR Cross-Reference] Draws on Joel 2:28-32. Consult the TCR rendering of that passage for the underlying Hebrew and the rationale for key translation choices.

Translator Notes

1. Joel's original text has 'servants and female servants' without the possessive 'my'; Peter's version (following the LXX variant) adds 'my' (mou), transforming social servants into God's own servants. This universalization of the Spirit breaks the social hierarchy: slaves and free, male and female all receive the prophetic Spirit. The addition of 'and they will prophesy' (kai prophēteusousin) is not in the Hebrew of Joel 2:29 — Peter extends the prophetic promise explicitly to the lowest social stratum.
2. [TCR Cross-Reference] References Joel 2:28-32 — the TCR OT rendering of that text provides the Hebrew source and explains the translation decisions involved.

Translator Notes

1. Peter adds 'above' (anō) and 'below' (katō) to Joel's text, emphasizing the cosmic scope of God's activity. The triad 'blood and fire and billows of smoke' may echo the Sinai theophany (Exodus 19:18) or anticipate the destruction of Jerusalem in AD 70. The Greek atmida kapnou ('vapor/billow of smoke') suggests thick, rising columns of smoke, not mere wisps.
2. [TCR Cross-Reference] Echoes Joel 2:28-32. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.
3. [TCR Cross-Reference] Echoes Exodus 19:18. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. Joel's Hebrew has 'great and terrible' (gadol v'nora); the LXX renders nora as epiphanē ('glorious, manifest, splendid') rather than 'terrible' — a significant interpretive shift from fear to revelation. The 'day of the Lord' (hēmeran kyriou) is a major prophetic concept throughout the Old Testament (Isaiah 2:12, Amos 5:18-20, Zephaniah 1:14-18), originally a day of judgment that Peter now connects to the events surrounding Jesus.
2. [TCR Cross-Reference] This verse quotes Joel 2:28-32 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.
3. [TCR Cross-Reference] This verse quotes Isaiah 2:12 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.
4. [TCR Cross-Reference] This verse quotes Amos 5:18-20 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.
5. [TCR Cross-Reference] This verse quotes Zephaniah 1:14-18 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.

Translator Notes

1. This is the climactic line of the Joel quotation and the hinge of Peter's sermon. In Joel, 'the Lord' (kyrios) translates YHWH — calling on the name of Israel's God. Peter will argue in verses 34-36 that Jesus is this Lord (kyrios), so that calling on the name of Jesus is calling on the name of the LORD. The verb sōthēsetai ('will be saved') encompasses both immediate rescue and eschatological salvation — the same word Paul will use in Romans 10:13 when quoting this same verse.
2. [TCR Cross-Reference] Quotes Joel 2:28-32. The TCR rendering of that OT passage preserves the Hebrew source text and documents the translation decisions behind it.

Translator Notes

1. Peter shifts from Joel's prophecy to its christological application. The designation 'the Nazarene' (ton Nazōraion) identifies Jesus by his hometown, grounding the theological claims in historical specificity. The triad 'mighty works and wonders and signs' (dynamesin kai terasin kai sēmeiois) covers the full range of Jesus's miraculous activity. Crucially, Peter says God performed these 'through him' (di' autou) — the miracles attest God's endorsement of Jesus. The appeal to the audience's own knowledge ('as you yourselves know') grounds the argument in shared public memory.

Translator Notes

1. Peter holds two truths in tension without resolving the paradox: Jesus's death was both 'the determined plan and foreknowledge of God' (tē hōrismenē boulē kai prognōsei tou theou) and the moral responsibility of those who crucified him. The 'lawless men' (anomōn) are the Roman soldiers who physically performed the crucifixion — 'lawless' because they were outside the Torah. But the 'you' (the Jewish audience) are also implicated: 'you put to death' (aneilate). Peter does not soften either side of this tension.

Translator Notes

1. The phrase 'agony of death' (tas ōdinas tou thanatou) literally means 'birth pangs of death' — the image is of death in labor, unable to hold its prey, forced to 'give birth' to the risen Jesus. The LXX of Psalm 18:5 (= 2 Samuel 22:6) uses the same phrase. The declaration 'it was not possible' (ouk ēn dynaton) is theologically profound: death's inability to hold Jesus is not merely historical but ontological — it lies in the nature of who Jesus is.
2. [TCR Cross-Reference] Echoes Psalm 18:5. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.
3. [TCR Cross-Reference] Echoes 2 Samuel 22:6. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. Peter now quotes Psalm 16:8-11 (LXX 15:8-11), attributing the words to David and applying them to Jesus. The Greek proorōmēn ('I saw beforehand, I kept before me') translates the Hebrew shiviti ('I have set'). The Lord at the right hand provides stability and protection — 'I will not be shaken' (mē saleuthō) expresses unshakeable confidence in divine presence.
2. [TCR Cross-Reference] This verse quotes Psalms 16:8-11 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.

Translator Notes

1. The LXX has 'tongue' (glōssa) where the Hebrew of Psalm 16:9 has 'glory' (kavod) — a significant textual divergence. The Hebrew kavod ('glory, weightiness') likely refers to the inner self or honor, which the LXX translators rendered as 'tongue' (perhaps reading kavod as kaved, 'liver,' an organ associated with deep emotion). The phrase 'my flesh will live in hope' (hē sarx mou kataskēnōsei ep' elpidi) becomes Peter's key proof text: if David's flesh 'lives in hope,' whose flesh found that hope fulfilled?
2. [TCR Cross-Reference] Quotes Psalms 16:8-11. The TCR rendering of that OT passage preserves the Hebrew source text and documents the translation decisions behind it.

Translator Notes

1. Hades (hadēn) is the Greek equivalent of the Hebrew Sheol — the realm of the dead, not the later Christian concept of hell as a place of punishment. 'Decay' (diaphthoran) translates the Hebrew shachat, which can mean 'pit' or 'corruption/decay.' The LXX's choice of diaphthora ('decay, corruption') is crucial for Peter's argument: David's body did see decay (v. 29), but Jesus's did not (v. 31). The term 'Holy One' (hosion) translates the Hebrew chasid ('faithful, loyal, devoted one').
2. [TCR Cross-Reference] Draws on Psalms 16:8-11. Consult the TCR rendering of that passage for the underlying Hebrew and the rationale for key translation choices.

Translator Notes

1. The 'paths of life' (hodous zōēs) implies not merely survival but the way to fullness of life — a path through death to resurrection. The final image — 'joy in your presence' (euphrosynēs meta tou prosōpou sou, literally 'gladness with your face') — is the ultimate hope: restored face-to-face relationship with God. The Psalm quotation ends on this note of joy, which Peter will now apply to the risen Jesus.
2. [TCR Cross-Reference] References Psalms 16:8-11 — the TCR OT rendering of that text provides the Hebrew source and explains the translation decisions involved.

Translator Notes

1. Peter's argument is straightforward: David cannot have been speaking about himself in Psalm 16 because David died, was buried, and his tomb is still present in Jerusalem — his body did see decay. The word parrhēsias ('confidently, boldly, with freedom of speech') indicates Peter is making a potentially controversial claim about Israel's greatest king. David's tomb was a well-known Jerusalem landmark, so the point is verifiable.
2. [TCR Cross-Reference] Echoes Psalm 16. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. Peter identifies David as a prophet, not merely a king and poet — this justifies reading the Psalms as prophetic. The oath refers to 2 Samuel 7:12-13 and Psalm 132:11, where God promises David an eternal dynasty. The Greek ek karpou tēs osphyos autou ('from the fruit of his loins') is a Hebraic idiom for physical descendants. We render this as 'one of his descendants' for natural modern English while noting the idiom.
2. [TCR Cross-Reference] This verse quotes 2 Samuel 7:12-13 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.
3. [TCR Cross-Reference] This verse quotes Psalm 132:11 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.

Translator Notes

1. Peter now makes the interpretive move explicit: David's words in Psalm 16 were prophetic speech about the Messiah's resurrection. The two key claims from Psalm 16:10 — not abandoned to Hades and no bodily decay — are applied to Jesus's resurrection. Peter's argument depends on the physical nature of the resurrection: Jesus's actual body did not decompose.
2. [TCR Cross-Reference] Quotes Psalm 16. The TCR rendering of that OT passage preserves the Hebrew source text and documents the translation decisions behind it.

Translator Notes

1. The sentence is emphatic in Greek: 'This Jesus' (touton ton Iēsoun) is placed first for emphasis — this specific historical person, not an abstract concept. The claim to be 'witnesses' (martyres) circles back to 1:8 — the apostles fulfill their commission as witnesses to the resurrection. The 'all' (pantes) includes the eleven standing with Peter, a claim that could be immediately verified or challenged by the audience.

Translator Notes

1. Peter connects the ascension (exaltation to God's right hand), the reception of the Spirit from the Father, and the Pentecost event in a single theological chain: Jesus is exalted → Jesus receives the Spirit from the Father → Jesus pours out the Spirit on his followers. The verb execheen ('poured out') directly echoes the Joel quotation in verse 17 ('I will pour out my Spirit'). The appeal to sensory evidence — 'what you both see and hear' (blepete kai akouete) — grounds the theological claim in observable phenomena.

Translator Notes

1. Peter now quotes Psalm 110:1 (LXX 109:1), the most frequently cited Old Testament text in the New Testament. The same argument applies: David did not ascend to heaven, so these words must refer to someone greater than David. The double 'Lord' (eipen ho kyrios tō kyriō mou) reflects the Hebrew 'the LORD (YHWH) said to my lord (adoni)' — David's lord is the Messiah, who sits at God's right hand.
2. [TCR Cross-Reference] Echoes Psalms 110:1. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. The image of enemies as a footstool reflects ancient Near Eastern conquest imagery — victorious kings literally placed their feet on the necks of conquered enemies (cf. Joshua 10:24). The Psalm envisions a period of reigning at God's right hand until all opposition is subdued. Peter leaves the implication hanging: if Jesus is now at God's right hand, then the subjugation of all enemies is underway.
2. [TCR Cross-Reference] This verse quotes Psalms 110:1 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.
3. [TCR Cross-Reference] This verse quotes Joshua 10:24 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.

Key Terms

Translator Notes

1. This is the sermon's climax. The adverb asphalōs ('with certainty, beyond doubt') demands intellectual assent, not mere emotional response. 'Lord and Christ' (kyrion kai christon) — the two titles Peter has argued for throughout the sermon converge: kyrios from Psalm 110:1 and christos from Psalm 16. The final phrase — 'this Jesus whom you crucified' (touton ton Iēsoun hon hymeis estaurōsate) — is deliberately confrontational, pressing the audience to reckon with the implications of having killed God's anointed one.
2. [TCR Cross-Reference] Quotes Psalm 110:1. The TCR rendering of that OT passage preserves the Hebrew source text and documents the translation decisions behind it.
3. [TCR Cross-Reference] Quotes Psalm 16. The TCR rendering of that OT passage preserves the Hebrew source text and documents the translation decisions behind it.

Translator Notes

1. The verb katenygēsan ('were pierced, were cut to the heart') is a powerful word describing deep emotional and spiritual conviction — it appears only here in the New Testament. The audience's question 'What should we do?' (ti poiēsōmen) is the proper response to conviction: not debate but action. Their address 'brothers' (adelphoi) shows they still consider Peter and the apostles fellow Jews.

Key Terms

Translator Notes

1. Peter's response contains four elements: repentance, baptism, forgiveness, and the gift of the Spirit. The verb metanoēsate ('repent') means to change one's mind and direction — the Greek equivalent of the Hebrew teshuvah ('return'). The preposition epi ('in/on/upon') with 'the name of Jesus Christ' indicates that baptism is performed on the authority of and in connection with Jesus. The preposition eis before 'forgiveness' can mean 'for the purpose of' or 'on the basis of' — both translations are grammatically possible.

Translator Notes

1. The scope of the promise expands in three concentric circles: 'you' (the present audience), 'your children' (the next generation), and 'all who are far off' (tous eis makran). The phrase 'those far off' echoes Isaiah 57:19 and Ephesians 2:13, 17 — it can refer to future generations, to diaspora Jews, or to Gentiles. Peter may not yet fully grasp the Gentile implications, but Luke's reader does. The final clause — 'everyone whom the Lord our God calls' — grounds the universal offer in divine initiative.
2. [TCR Cross-Reference] Echoes Isaiah 57:19. See the TCR's OT rendering for the Hebrew behind this passage and the translation rationale.

Translator Notes

1. Luke summarizes the rest of Peter's sermon rather than recording it fully — 'many other words' (heterois logois pleiosin) indicates this is an excerpt. The verb diemartyrato ('solemnly testified') carries legal weight, while parekalei ('kept urging, exhorting') is imperfect tense indicating ongoing, persistent appeal. The phrase 'crooked generation' (geneas tēs skolias) echoes Moses' words in Deuteronomy 32:5 and Jesus's own language in Matthew 17:17.
2. [TCR Cross-Reference] This verse quotes Deuteronomy 32:5 — see the TCR rendering of that passage for the Hebrew source text and translation decisions.

Translator Notes

1. The number 'about three thousand' (hōsei trischiliai) represents a massive response to a single sermon. The passive prosetethēsan ('were added') implies divine agency — God adds to the community. The word psychai ('souls/people') is used in the Semitic sense of 'persons,' not in the Greek philosophical sense of immortal souls. The logistics of baptizing three thousand people in a single day likely involved the numerous mikva'ot (ritual immersion pools) near the Temple, which have been archaeologically confirmed.

Key Terms

Translator Notes

1. This verse is often called the four marks of the early church: teaching (didachē), fellowship (koinōnia), breaking of bread (klasis tou artou), and prayers (proseuchais). The verb proskarterountes ('devoting themselves') is the same word used in 1:14 — the persistence that characterized the pre-Pentecost community continues and intensifies. 'Breaking of bread' may refer to ordinary communal meals, the Lord's Supper, or both — Luke does not distinguish. The plural 'prayers' (proseuchais) may indicate set times of prayer, possibly following the Jewish daily prayer schedule.

Translator Notes

1. The word phobos ('fear, awe, reverence') here indicates reverential awe rather than terror — the community lived with a sense of the sacred. The 'wonders and signs' (terata kai sēmeia) performed through the apostles echo the description of Jesus's own ministry in verse 22, showing continuity between Jesus's work and the apostles' work through the Spirit. The imperfect tense egineto ('were being done') indicates ongoing, repeated miraculous activity.

Translator Notes

1. The phrase epi to auto ('together, in the same place') echoes verses 1 and 1:15 — unity of place reflects unity of heart. The economic sharing described here — 'held everything in common' (eichon hapanta koina) — is voluntary community, not enforced communism. The sharing arises from the koinōnia described in verse 42, not from external compulsion. Luke presents this as an ideal, not necessarily as a permanent economic model.

Translator Notes

1. Luke distinguishes between 'possessions' (ktēmata, typically real property like land) and 'belongings' (hyparxeis, personal goods and assets). The imperfect tenses (epipraskon, diemerizon) indicate ongoing, repeated action — they sold as needs arose, not in a single liquidation event. Distribution was based on need (chreia), not equality — a principle of sufficiency rather than uniformity.

Translator Notes

1. The early believers maintained a dual pattern of worship: public gathering in the temple (en tō hierō, referring to the temple courts, especially Solomon's Portico per 3:11) and private fellowship in homes (kat' oikon). They did not abandon Jewish temple worship but supplemented it with distinctly Christian home gatherings. The word aphelotēti ('sincerity, simplicity, generosity') occurs only here in the New Testament — it suggests an unaffected, genuine quality of heart free from pretense.

Translator Notes

1. The chapter ends with two complementary realities: human praise ('praising God') and divine growth ('the Lord was adding'). The present participle sōzomenous ('those being saved') indicates an ongoing process, not a completed transaction — salvation in Acts is both an event and a journey. The phrase epi to auto ('to their number, together') echoes the opening of the chapter, creating a literary frame: the community that gathered in verse 1 has grown from 120 to over 3,000.
2. Luke does not use the word 'church' (ekklēsia) here, though the KJV adds it. The SBLGNT simply has 'adding together' — the community is described by its life rather than by a title.