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.
Glorified not himself - did not assume the glory of the priestly office without the call of God (John 8:54).
But he that said - i:e., the Father appointed Him to His glorified priesthood (Hebrews 5:10). This appointment was involved in, and resulted from, His Sonship, which qualified Him for it. None else could have fulfilled such an office (Hebrews 10:5-9). The connection of Sonship and priesthood is typified in the title [kohaniym] priests being given to David's sons (2 Samuel 8:18). Christ did not constitute Himself the Son of God, but was from everlasting the only-begotten of the Father.