Acts 13:33

has been fulfilled by God for us their children, when he raised Jesus. As it is written in the second psalm, thou art my son, to-day have I become thy father.

Hebrews 5:5

Similarly Christ was not raised to the glory of the high priesthood by himself but by Him who declared to him, Thou art my son, to-day have I become thy father.

Hebrews 1:5-6

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

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, to-day have I become thy father'? Or again, 'I will be a father to him, and he shall be a son to me'?
Hebrews 5:5
Similarly Christ was not raised to the glory of the high priesthood by himself but by Him who declared to him, Thou art my son, to-day have I become thy father.