Psalm 110:4 Yahweh has sworn, and will not change his mind:
“You are a priest forever in the order of Melchizedek.”
Hebrews 5:5 So also Christ didn’t glorify himself to be made a high priest, but it was he who said to him,
“You are my Son.
Today I have become your father.”
6 As he says also in another place,
“You are a priest forever,
after the order of Melchizedek.”