Hebrews 7:20LXX

18For there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof.

19For the law made nothing perfect, but the bringing in of a better hope ; by the which we draw nigh unto God.

20And inasmuch as not without an oath :

21(For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou a priest for ever after the order of Melchisedec:)

22By so much was Jesus made a surety of a better testament.