The passage
      v44. Peter was still in the middle of his gospel presentation when the Gentiles receive the Holy Spirit. The reception is similar to that of the apostles - sudden and unexpected. This was a significant occurrence and was without the usual exhortation, "repent and be baptized in order to receive the gift of the Holy Spirit." "All who heard the message" received the gift.
      v45-46. The significance of the event is not wasted on the Jewish believers who accompanied Peter. They were "astonished", for the Spirit came on the Gentiles in exactly the same way as He came on the apostles at Pentecost. They "heard them speaking in tongues and praising God", cf. 2:11. The phrase "praising God" literally means "magnifying God", which probably aligns with the description given on the day of Pentecost, "speaking.... the mighty acts of God." The Spirit's coming on the Gentiles in exactly the same way as on the apostles, removed any doubt that the doors of the kingdom are now open for Gentiles as well as Jews. In fact, this sign further evidenced the presence of the kingdom, cf. Zech.8:23. Again, we are unsure what "speaking in tongues" was like. Clearly there is language content to the experience, in that the onlookers heard them "glorifying God". In fact, the experience probably paralleled Pentecost where "each one heard them speaking in their own language."
      v47-48. Peter obviously senses the importance of the occasion, and that by baptizing these Gentile believers he is moving into new territory. Still, who could argue against baptism? Cornelius and his friends had just received the Spirit. The normal order of events are: the preaching of the gospel, a response of repentance and belief, water baptism for the remission of sins (a sign of repentance and its consequence, the washing of forgiveness), and the gift of the Holy Spirit. Laying on of hands (a sign of prayer) may precede the gift of the Spirit, but was obviously not an essential element. Clearly, repentance and belief were present, although not stated here, cf. 11:17, 15:7-9. Water baptism was the only event out of order, and was still administered even though the Gentiles had received the Spirit. One doesn't supersede the other.
      The baptism was administered "in the name of Jesus Christ", cf. 2:38. This could just mean that Jesus' name, his divine character, is declared over the person to be baptized, although it is more likely that "baptizing them in the name", cf. Matt.28:19, carries the idea of instruction in gospel truth. The person doing the baptizing, in this case "the circumcised believers who came with Peter", would most likely hear the content of the converts repentance, confirm its truth, or restate it where necessary. In this way the convert is immersed ("baptized" figuratively) into the truth of Jesus, into the "name", as well as immersed in water as an outward expression of their repentance ("a baptism of repentance for the forgiveness of sins").

That little extra
      The Billy Graham tract, illustrating the cross spanning the gulf of hell, left itself open to a bit of reworking. It is very easy to draw a little segment on the end of the cross representing the necessary extra "particular" that enables a complete crossing from this world to heaven. Without the "particular" we are lost.
      There are still those who argue that water baptism is an essential element for eternal blessing - the important extra. Yet, most Christians hold that it is baptism in Jesus, in the sense of identification with the truth of Jesus in the gospel, that saves.
      There are many other extras. Some demand the baptism of the Holy Spirit, evidenced in the speaking of tongues through the laying on of hands. In the presence of someone who pushes this extra we can end up feeling like a second-grade Christian. Of course, such a view fails to understand the theology of the book of Acts. The dawning of the kingdom, with it's blessing of the "promised Holy Spirit" (God's indwelling presence in those who believe), is poured out on all who believe, Jew and Gentile alike. All who believe, receive the gift of the Holy Spirit.
      The replay of the miracle of Pentecost for Cornelius and his friends, does not serve to support "second-blessing" theology, but rather serves to remind all believers of the blessing we already possess in Christ through faith.

v45
      ek peritomhV (h) "the circumcised believers" - of circumcision. Possibly referring to the circumcision party, although probably here just "Jewish believers."
      exesthsan (existhmi) aor. "were astonished" - were amazed, mad, out of mind, astonished / to remove from a standing position. The outpouring of God's blessing upon the Gentiles was totally unexpected. "Absolutely amazed", Phillips.
      ekkecutai (ekcew) perf. pas. "had been poured out" - has been poured out. The perfect tense indicating a past action with ongoing consequences. "The gift of the Spirit had been given so freely and generously to people who were not Jews", Barclay.

v46
      hkouon (akouw) imperf. "they heard" - they were hearing. The imperfect expressing continued action.
      lalountwn (lalew) pres. part. "speaking" - The participle may form a temporal clause; "when they heard them speaking."
      glwssaiV (a) "tongues" - tongue, language. In the New Testament, in the plural, it refers to the utterance of those caught up in spiritual ecstasy. As at Pentecost, the utterance has language content such that it can be understood, although its ecstatic nature does confuse. The onlookers at least understood that Cornelius and his friends were "praising God", or as noted below, "proclaimed the mighty works of God." The Western text adds "other" tongues, cf. 2:4. This is, in itself, an interesting phrase in that it may imply a possible difference in the Pentecost form of tongues from the form recorded by Paul in Corinthians. Do the editors of the Western text understand such a difference and want to align Cornelius' experience with that of the apostles at Pentecost? "They heard them prophesying ecstatically."
      megalunontwn ton qeon "praising God" - enlarging, magnifying increasing, exalting. The participle is functioning in apposition to the participle "speaking", defining what they were speaking. The word is probably too general to carry the specific meaning of "praising." The word "magnify" is far better, so "glorify". In 2:11 those speaking in tongues proclaimed the mighty works of God. They "enlarged" the information concerning God, albeit in an ecstatic form. So, the phrase here is likely to carry a similar meaning rather than just "praising God." "Glorifying God", Phillips.
      apekriqh (apokrinomai) aor. pas. "[Peter] said" - answered. Peter is "answering" the situation. "At this Peter asked", Moffatt.

v47
      mhti "-" - not. Used in a question which expects a negative answer.
      kwlusai (kuluw) aor. inf. "keep" - [is anyone able] to forbid, hinder, refuse. A natural infinitive, epexegetic in function. It is unlikely that the believing Jews were unwilling to accept Gentiles into their fellowship, but they would expect normal procedure to be followed: instruction, circumcision, water baptism, followed by the gift of the Spirit through the laying on of hands (prayer). All this was turned on its head. So, who could refuse water baptism, the sign of repentance, for those already baptized with Spirit?
      tou mh baptisqhnai (baptizw) inf. "from being baptized" - [the water] not to dip, immerse. The articular infinitive forms a purpose clause. "Can anyone refuse water for (the purpose of) the baptism of these people", Moffatt.
      oiJtineV "they" - who. "Men (people) such as have received", Moule.
      wJV kai hJmeiV "just as we have" - as also we. This is an important statement. The Gentiles' reception of the Spirit, in exactly the same way as the apostles' reception, authorizes the full right of access of Gentiles into the new Israel. It is likely that Peter's desire to baptize these new believers serves as an apostolic confirmation of this divine initiative. The incident can't really be used to support the argument that water baptism is essential to salvation, or that it is a sign of the giving of the Holy Spirit (water baptism is a sign of repentance for the forgiveness of sins).