Hebrews 7:20-22

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’ ”).

22And so [because of the oath’s greater strength and force] Jesus has become the certain guarantee of a better covenant [a more excellent and more advantageous agreement; one that will never be replaced or annulled].