Hebrews 6:16-18

ERV(i) 16 For men swear by the greater: and in every dispute of theirs the oath is final for confirmation. 17 Wherein God, being minded to shew more abundantly unto the heirs of the promise the immutability of his counsel, interposed with an oath: 18 that by two immutable things, in which it is impossible for God to lie, we may have a strong encouragement, who have fled for refuge to lay hold of the hope set before us;