The Lord sware and will not repent — Hence also it appears, that his is an unchangeable priesthood.
Related Commentaries of Hebrews 7:21
Hebrews 7:21
21 (For those priests were made withoutb an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:)