29 Men and brethren, let me freely speak unto you of the patriarch David, that he is both dead and buried, and his sepulchre is with us unto this day.
30 Therefore being a prophet, and knowing that God had sworn with an oath to him, that of the fruit of his loins, according to the flesh, he would raise up Christ to sit on his throne;
31 He seeing this before spake of the resurrection of Christ, that his soul was not left in hell, neither his flesh did see corruption.
32 This Jesus hath God raised up, whereof we all are witnesses.
33 Therefore being by the right hand of God exalted, and having received of the Father the promise of the Holy Ghost, he hath shed forth this, which ye now see and hear.
34 For David is not ascended into the heavens: but he saith himself, The Lord said unto my Lord, Sit thou on my right hand, 35 Until I make thy foes thy footstool.
36 Therefore let all the house of Israel know assuredly, that God hath made the same Jesus, whom ye have crucified, both Lord and Christ.
The context of Acts 2 to me is clear that he was contrasting David and Jesus, one was resurrected and ascended to heaven, the other remained in his grave dead and buried.
That is the problem.
"For David
did not ascend into heaven. But he says,
‘Adonai said to my Lord,
“Sit at my right hand
until I make your enemies a footstool for your feet.”’
Peter makes no claim about David's then position in Paradise. He rightly pointed out David did not ascend when David died. He could not. Paradise was banned, until the Cross. Paradise is not Abraham's bosom. Jesus did not tell the thief, "today thou shalt be with me in Abraham's bosom." The thief was with the Lord God in Paradise. No one was in Abraham's bosom. Christ does not rule from Abraham's bosom.
"Adonai said to my Lord,
“Sit at my right hand
until I make your enemies a footstool for your feet."
David and Peter were declaring that Jesus whom they just crucified was the promised Messiah.
Peter was not making a doctrinal statement about the OT church being led captive from Abraham's bosom and was now seated in Paradise. Nor was Peter making a doctrinal statement they were not seated with Christ in Paradise. Peter was not talking about Abraham's bosom nor Paradise. Peter was not even talking about David. He was pointing out that David, hundreds of years ago, promised a Messiah, and Jesus Christ who they just killed was that Messiah and Jesus was sitting next to the Lord, just as David wrote. Christ was as much the Messiah as David and his tomb were real.
This is not a proof text about David waiting to be resurrected, where Paradise is, nor anything about the OT church. David was not talking about himself. He was talking about Jesus Christ. Peter was not talking about David. He was talking about Jesus Christ.
Peter was not contrasting David with Jesus Christ. If that were the case then David was not contrasting himself with Christ, but proclaiming that David would raise up and be the Messiah. No one would take Peter's word, because that was the point. David was not the Messiah. Every one already knew that and it was an indisputable fact. Peter did not have to convince any one of that fact. They were waiting for that Messiah that was, not David. Peter was trying to convince them by David's authority and Holy Spirit inspiration of David's writings, that Jesus Christ was the promised Messiah who would sit with Adonai in Paradise.
David never ascended to heaven, because no one could until Messiah ascended. It was not that any one could not. It was that no corruptible body could. Enoch ascended. Elijah ascended. They had incorruptible bodies to enter Paradise. Every one else had to go to Abraham's bosom in sheol as David rightly pointed out. Peter was not trying to explain that people could now do that. First he had to convince them that Jesus Christ they just crucified had ascended Himself. No one would accept one without the other.
They still rejected Jesus as the Messiah. The point that the OT church already ascended would have gone over like a led balloon. Seems even some who accept Jesus is ascended, do not accept Paradise is where Jesus ascended to. Even though He declared that on the Cross. What verses point out Paradise is anywhere else besides the temple of God, holy mount zion, a city not made by hands in the heavens?