One of the thrilling treasures that one can find while reading the Old Testament is a conversation between the Father and the Son before the Son was revealed – speaking to one another through the mouth of a prophet! It is a pearl of great price to be able to recognize the voice of the Son making a request to the Father in the following prophecy from Psalm 102:23-24a, and then to recognize the voice of the Father replying to the Son in verses 24b-28. We know that these latter verses are the Father speaking to the Son because the author of the New Testament book of Hebrews plainly says so (Heb. 1:10-12).
First, the Son makes the same request of the Father that he made in the Garden of Gethsemene; namely, that he would not be made to die early (vv. 23-24a):
He weakened my strength in the way; He shortened my days. I said, “O my God, take me not away in the midst of my days!”
Then we have the Father’s response to the Son (vv. 24b-27):
"Your years are throughout all generations. Of old have you laid the foundation of the earth, and the heavens are the work of your hands. They shall perish, but you shall endure. Yea, all of them shall wax old like a garment; as a vesture shall you change them, and they shall be changed. But you are the same, and your years have no end.”
So, the Son foretells of his prayer for life, and the Father promises the Son that he will live forever. And they do this through the same prophet, during the same prophecy!
David must have wondered who was talking through him when the Spirit took over his mouth and said these things. He knew it was the Spirit (2Sam. 23:1-2), and he also knew that only at a later time would he understand what he was saying (1Pet. 1:10-12). But as for us, it is given to us to know the ones who were speaking through David because the same Spirit that used his voice has used ours and has given us the knowledge that David wanted but didn’t have: the knowledge of the Father and the Son.
