Acts 13:33

"how that God fulfilled it for us their children in raising up Jesus; as it is also written in the second Psalm, "Thou art my son, today have I become thy Father.

Hebrews 5:5

So even the Christ was not raised to the high glory of the priesthood by himself, but on the contrary by Him who said to him. Thou art my Son; this day have I become thy Father;

Hebrews 1:5-6

For to what angel did God ever say, Thou art my son; this day have I become thy Father? and again, I will be a father to him, and he shall be to me a son?

Treasury of Scripture Knowledge

Summary

God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee.

Bible References

Thou art

Hebrews 1:5
For to what angel did God ever say, Thou art my son; this day have I become thy Father? and again, I will be a father to him, and he shall be to me a son?
Hebrews 5:5
So even the Christ was not raised to the high glory of the priesthood by himself, but on the contrary by Him who said to him. Thou art my Son; this day have I become thy Father;