said unto them
The theme of Peter's sermon at Pentecost is stated in (Acts 2:36). It is, that Jesus is the Messiah. No message could have been more unwelcome to the Jews who had rejected His Messianic claims, and crucified Him. Peter, therefore, does not announce his theme until he has covered every possible Jewish objection. The point of difficulty with the Jews was the apparent failure of the clear and repeated prophetic promise of a regathered Israel established in their own land under their covenanted King (for example, (Isaiah 11:10-12); (Jeremiah 23:5-8); (Ezekiel 37:21-18). Instead of explaining, as Rome first taught, followed by some Protestant commentators, that the covenant and promises were to be fulfilled in the church in a so-called "spiritual" sense, Peter shows (Acts 2:25-32) from Psalm 16 that David himself understood that the dead and risen Christ would fulfil the covenant and sit on his throne (Luke 1:32); (Luke 1:33). In precisely the same way James (Acts 15:14-17) met the same difficulty.
See "Kingdom (Old Testament)," (Zechariah 12:8).
(New Testament), (Luke 1:33); (1 Corinthians 15:24).