Hebrews 7:3

7:3 Without father, without mother, without genealogy, he has neither beginning of days nor end of life but is like the son of God, and he remains a priest for all time.

Hebrews 7:16-17

7:16 who has become a priest not by a legal regulation about physical descent but by the power of an indestructible life. 7:17 For here is the testimony about him: “You are a priest forever in the order of Melchizedek.”

Hebrews 7:28

7:28 For the law appoints as high priests men subject to weakness, but the word of solemn affirmation that came after the law appoints a son made perfect forever.