Hebrews 5:5-6

5:5 So also Christ did not glorify himself in becoming high priest, but the one who glorified him was God, who said to him, “You are my Son! Today I have fathered you,” 5:6 as also in another place God says, “You are a priest forever in the order of Melchizedek.”

Hebrews 6:20

6:20 where Jesus our forerunner entered on our behalf, since he became a priest forever in the order of Melchizedek.