For I am the LORD

For I am the LORD, I change not; therefore ye sons of Jacob are not consumed. Mal 3:6

God is not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do it? or hath he spoken, and shall he not make it good? Num 23:19

But thou art the same, and thy years shall have no end. Ps 102:27

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: Heb 6:18

Jesus Christ the same yesterday, and to day, and for ever. Heb 13:8

Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning. James 1:17

My covenant will I not break, nor alter the thing that is gone out of my lips. Ps 89:34

The Hebrew words for "I Change not" is Lo Shanithi.

OT:8138 shanah

(shaw-naw'); a primitive root; to fold, i.e. duplicate (literally or figuratively); by implication, to transmute (transitive or intransitive):

KJV - do (speak, strike) again, alter, double, (be given to) change, disguise, (be) diverse, pervert, prefer, repeat, return, do the second time.

OT:3808 lo' (lo); or low' (lo); or loh (Deut 3:11) (lo); a primitive particle; not (the simple or abs. negation); by implication, no; often used with other particles (as follows):

KJV - X before, + or else, ere, + except, ignorant, much, less, nay, neither, never, no ([-ne], -r, [-thing]), (X as though ... [can-], for) not (out of), of nought, otherwise, out of, + surely, + as truly as, + of a truth, + verily, for want, + whether, without.
(Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.)

The Greek word for Immutable is Ametatheton.

NT:276 ametathetos

(am-et-ath'-et-os); from NT:1 (as a negative particle) and a derivative of NT:3346; unchangeable, or (neuter as abstract) unchangeability:

KJV - immutable (-ility)
(Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.)