Hebrews 1:5

Thou are my Son; see the following note on the quotation from 2 Samuel 7:14.

This day have I begotten thee; some understand these words of Christ's eternal sonship, supposing that with God, to whom time is nothing, "this day" may include eternity. But they are more commonly taken in a declarative sense of the manifestation which the Father made of Christ's sonship by his resurrection and glorification. So the apostle Paul seems to use them, Acts 13:33. Compare Romans 1:4; Colossians 1:18.

I will be to him a Father, and he shall be to me a Son; 2 Samuel 7:14, compared with Psalms 89:26-27. This promise was made not to Solomon as an individual, but to David's whole royal line, at the head of which, after David, Solomon stood, and which led to and terminated in Christ. Luke 1:32-33. God took David's house into the relation of sonship to himself, in the sense of making his seed heirs to his throne by an inalienable title. Psalms 89:28-29; Psalms 89:33-37. The lower sonship of David and Solomon, moreover, foreshadowed the higher sonship of Christ, in whom alone the promise here, and in Psalms 2:7, is perfectly fulfilled.