Thematic Bible: Being made without an oath

Then again, the appointment of this new priest was ratified by an oath, which is not so with the Levitical priests, but his appointment was ratified by an oath, when God said to him-- 'The Lord has sworn, and will not change, "Thou art a priest for all time."' And the oath shows the corresponding superiority of the Covenant of which Jesus is appointed the surety.