Acts 13:33 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.
Says that psalm had to be fulfilled, and in the place the Son adressed by the Father as God
Heb 1:8 But unto the Son he saith, (adressed here)
But (spoken of here)
Psalm 45:6 Thy throne, O God, is for ever and ever: the sceptre of thy kingdom is a right sceptre.
Psalm 47:6 Thou lovest righteousness, and hatest wickedness: therefore God, thy God, hath anointed thee with the oil of gladness above thy fellows.
God thy God, or Christ's God (in otherwords) as the head of Christ is God, and there especially fulfilling the psalm, as God raised Jesus up again where he by the Father (who subjected all things under him) adresses the Son as God
John 20:17 Jesus saith unto her, Touch me not; for I am not yet ascended to my Father:
but go to my brethren, and say unto them, I ascend unto my Father, and your Father; and to my God, and your God.
And when He ascends we see,
Heb 1:8 But unto the Son he saith, Thy throne, O God, is for ever and ever: a sceptre of righteousness is the sceptre of thy kingdom.
Even as the psalm of David shows, The LORD saith to MY Lord (in the same aslo) where he is adressed differently there but as equally is he adressed in Psalm 45:6 by the Father as God (and it is God thy God) as the head of Christ is God who is shown saying it. David speaking of the resurrection of Jesus Christ, fulfilling the second Psalm (in the same) and then the NT shows in the one who hath immortality those same things in the hereafter in the one lifted up, and in the priesthood in Psalm 110:4 after the order of Melchizedek but sworn in by the Father in it. Not taking this honour to himself but in the same sense as Aaron glorified not himself not to be made either but rather, it was "said unto Him" in both things
Heb 5:5 So also Christ glorified not himself to be made an high priest;
but he that said unto him, Thou art my Son, to day have I begotten thee.
As God sent the Son (the Word made flesh) God raised Jesus up again to be made an high priest, brought forth into this world and begotten from the dead. God put all things under the Son but they also say, it is manifest that He is excepted that put all things under him.