Commentaries:
The important thing here is something that is not even mentioned. No circumcision is required, which becomes important later. To whom does God reveal that one need not be circumcised to receive the Holy Spirit? They are all astonished, but Peter gives the authoritative answer, and it is to him that God speaks throughout these events. God does not reveal this to the other eleven but to Peter, first among equals, preeminent among them.
John W. Ritenbaugh
Unity (Part 2): God's Pattern of Leadership
The clear implication of Leviticus 13:47-59 is that some, though not all, leprous garments became clean. Peter's vision of "all kinds of four-footed animals of the earth, wild beasts, creeping things, and birds of the air" (Acts 10:12) speaks to this point. God made it clear that He was capable of cleansing the Gentiles, but never said He had cleansed all of them at this time. Notice His admonition to Peter: "What God has cleansed you must not call common" (verse 15). Peter got the picture when he met Cornelius shortly after, telling the Roman centurion: "In truth I perceive that God shows no partiality. But in every nation whoever fears Him and works righteousness is accepted by Him" (verses 34, 35). While God calls from "every nation," only some, those who fear and obey, are acceptable to Him.
In verse 36, Peter interjects a vital idea: Christ "is Lord of all." Verse 45 records that the "Holy Spirit had been poured out on the Gentiles also." The "apostles and brethren who were in Judea" (Acts 11:1) came to understand that "God has also granted to the Gentiles repentance to life" (verse 18).
Charles Whitaker
The Mixed Multitude
Other Forerunner Commentary entries containing Acts 10:45:
Matthew 25:1-13
Acts 2:3
Acts 9:17
Acts 10:9-16
Acts 15:1
Acts 19:6
Galatians 3:2
1 Timothy 4:14
2 Timothy 1:6-7