Acts 2:25

For David saith concerning him, I beheld the Lord always before my face; For he is on my right hand, that I should not be moved: Therefore my heart was glad, and my tongue rejoiced; Moreover my flesh also shall dwell in hope: Because thou wilt not leave my soul unto Hades, Neither wilt thou give thy Holy One to see corruption. Thou madest known unto me the ways of life; Thou shalt make me full of gladness with thy countenance.

These words are from Psalms 16:8ff. In this Psalm, David spoke in the first person, as if the glorious promises concerned himself; but actually they regarded great David's greater Son, the Lord Jesus Christ, there having been no fulfillment whatever of these words in the instance of King David himself. It is absolutely certain that this passage from the Old Testament prophesies a resurrection of someone, for it is only by a resurrection that one could descend into the grave (Hades) and not see corruption. The inspired Peter correctly applied it to the resurrection of Christ, an event the Lord had repeatedly, at least four different times, prophesied and elaborated for the Twelve. The proof absolute that this Psalm cannot refer to David was present for all to see right there in Jerusalem in the tomb of David which still enshrined his dust.