“Brethren, I may say to you freely of the patriarch David, that he both died and was buried, and his tomb is with us to this day. Being therefore a prophet, and knowing that God had sworn with an oath to him, that of the fruit of his loins he would set one on his throne; he foreseeing this spoke of the resurrection of the Christ, that neither was he left to Hades, nor did his flesh see corruption.”
He declares that this Psalm could not literally apply to David because David did die, and was buried, and because his body did see corruption, as was evidenced by the fact that his tomb was with them to that day. He therefore declares that the literal fulfilment of the Psalm requires its fulfilment of another ‘David'. This fulfilment having not happened to David, it must necessarily happen to the coming David, His Holy One, the Messiah. In this way it would happen to David in his descendant.
Here we have another case of prophecy where the original prophecy was part fulfilled, while in the fullest sense the prophecy awaited a later time. Here, says Peter, David knew that in accordance with God's promise, God would raise up a son to David who would be ‘the everlasting King' (2 Samuel 7:12-13). The promises of God were regularly of ‘everlastingness' in the Old Testament. They did not always think it through but it was there. And that being so David had known that such a king could not possibly be held by death or the grave, otherwise he could not reign for ever. The future ‘David', therefore, could not finally be ‘left in Hades', nor could His flesh finally corrupt, otherwise the promise would fail. Thus, says Peter, as the Coming King is Jesus Who had been put to death, as they all knew, His resurrection was inevitable. He must rise from the dead otherwise He could not be the everlasting King. In this argument we might sense the teaching of Jesus after His resurrection and the influence of Isaiah 53:10-12 connected with Acts 9:6-7.
Peter's interpretation brings out an important aspect of prophecy. The prophets were often prophesying of future trends rather than of specific events. Yet it is again and again remarkable how in the later fulfilment of these trends actual details are fulfilled in a way probably not expected by the prophet. A very good example of this is found in Psalms 22:14-18. This passage is another example.
His emphasis on the fact that David died, and was buried and that they knew this because his tomb was with them to this day was probably intended to remind them of the empty Tomb which Peter would remember so vividly. It suggests also that the account of Jesus' empty tomb was not only common knowledge (as we know it was, otherwise the soldiers would not have been bribed to put the blame on the disciples - Matthew 28:13), but was also such a talking point at this time that he did not feel that he had to draw attention to it when describing the tomb of David. (It was only two months later. Plenty of time for the story to get around Jerusalem, and not long enough for it to have been forgotten). He believed that they would automatically draw the parallel. Compare and contrast Paul's declaration that Jesus ‘died --- and was buried -- and rose again' (1 Corinthians 15:3-4) which is in direct contrast to what is said of David here.