Hebrews 7:21
but Jesus became a priest with an oath when God told him, "The Lord has taken an oath and will not change his mind. You are a priest forever."
Psalm 110:4
The LORD took an oath and will never recant: "You are a priest forever, after the manner of Melchizedek."
Hebrews 7:17
For it is declared about him, "You are a priest forever according to the order of Melchizedek."
1 Samuel 15:29
Moreover, the Glory of Israel does not lie or change his mind, for he's not a man that he should change his mind."
Hebrews 6:16-18
For people swear by someone greater than themselves, and an oath given as confirmation puts an end to all argument.