Unchangeable.

Wherein God, willing more abundantly to show unto the heirs of promise the immutability of his counsel, confirmed it by an oath: that by two IMMUTABLE things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us. ( Hebrews 6:17-18 )

Dictionary of Words from the King James Bible. Public Domain. Copy freely.