King James Version
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 art a priest for ever after the order of Melchisedec:)English Standard Version
but this one was made a priest with an oath by the one who said to him: "The Lord has sworn and will not change his mind, 'You are a priest forever.'"New International Version
but he became a priest with an oath when God said to him: "The Lord has sworn and will not change his mind: 'You are a priest forever.'"