ἀμετάθετος ametáthetos

Meaning

unchangeable, or (neuter as abstract) unchangeability

In the King James Version: immutable(-ility)

Derivation: from G1 (Α) (as a negative particle) and a derivative of G3346 (μετατίθημι);

Where it is used

• Hebrews 6:17 So when God wanted to make the unchanging nature of His purpose very clear to the heirs of the promise, He guaranteed it with an oath.
• Hebrews 6:18 Thus by two unchangeable things in which it is impossible for God to lie, we who have fled to take hold of the hope set before us may be strongly encouraged.