Hebrews 7:20-24

20And inasmuch as He was not made priest without an oath

21(for they have become priests without an oath, but He with an oath by Him who said to Him: “The Lord has sworn And will not relent, ‘You are a priest forever According to the order of Melchizedek’ ”),

22by so much more Jesus has become a surety of a better covenant.

23Also there were many priests, because they were prevented by death from continuing.

24But He, because He continues forever, has an unchangeable priesthood.