Part of the ongoing Verse Quick Reference project.

1Sa 15:29 And also the Strength of Israel will not lie nor relent. For He is not a man, that He should relent.”

1 Samuel 15:29 is often used to advocate the idea that God is immutable, not only immutable in His word but also in His very essence. Here is the context of the entire chapter:

King Saul has just violated God’s command not to take spoils of war.

1Sa 15:9 But Saul and the people spared Agag, and the best of the sheep, and of the oxen, and of the fatlings, and the lambs, and all that was good, and would not utterly destroy them: but every thing that was vile and refuse, that they destroyed utterly.
1Sa 15:10 Then came the word of the LORD unto Samuel, saying,
1Sa 15:11 It repenteth me that I have set up Saul to be king: for he is turned back from following me, and hath not performed my commandments. And it grieved Samuel; and he cried unto the LORD all night.

This leads God directly to “repenting” of having made Saul the king of Israel. Samuel hears God’s message and the next morning confronts Saul on his spoils of war. Samuel explains to Saul that “Because thou hast rejected the word of the LORD, he hath also rejected thee from being king.” Saul immediately repents, and asks for mercy (for his kingdom to not be taken away):

1Sa 15:24 And Saul said unto Samuel, I have sinned: for I have transgressed the commandment of the LORD, and thy words: because I feared the people, and obeyed their voice.
1Sa 15:25 Now therefore, I pray thee, pardon my sin, and turn again with me, that I may worship the LORD.
Notice Saul’s deep repentance. Saul seeks pardon and wants to go worship God. But this is denied. Samuel says:
1Sa 15:28 And Samuel said unto him, The LORD hath rent the kingdom of Israel from thee this day, and hath given it to a neighbour of thine, that is better than thou.
1Sa 15:29 And also the Strength of Israel will not lie nor repent: for he is not a man, that he should repent.

The context of God not repenting is “repenting that He made Saul king.” When God says He will not repent, God is saying “I will not repent of repenting that I made Saul king (taking his kingdom away).” God is not making a general claim of immutability. God is making the claim that Saul cannot expect to convince God to give him back the kingdom. God has made up his mind.

The statement needs to be understood in context, and not carte blanche applied to everything. In the direct context, not God says says that He repents, but also the narrator. It is the same word used in verse 29. The text is not contradicting itself, and it is not suggesting to elevate the words of Samuel over the words of God and the narrator. Samuel is definitely not launching into a off the cuff sermon on advanced metaphysics to Saul. Reading comprehension does not support 1 Samuel 15:29 as a prooftext for immutability.