Hebrews 7:16-21

16who has become a priest, not on the basis of a physical and legal requirement in the Law [concerning his ancestry as a descendant of Levi], but on the basis of the power of an indestructible and endless life.

17For it is attested [by God] of Him, “You (Christ) are a Priest forever According to the order of Melchizedek.”

18For, on the one hand, a former commandment is cancelled because of its weakness and uselessness [because of its inability to justify the sinner before God]

19(for the Law never made anything perfect); while on the other hand a better hope is introduced through which we now continually draw near to God.

20And indeed it was not without the taking of an oath [that Christ was made priest]

21(for those Levites who formerly became priests [received their office] without [its being confirmed by the taking of] an oath, but this One [was designated] with an oath through the One who said to Him, “The Lord has sworn And will not change His mind or regret it, ‘You (Christ) are a Priest forever’ ”).