1 Samuel 15:11

15:11 “I regret that I have made Saul king, for he has turned away from me and has not done what I told him to do.” Samuel became angry and he cried out to the Lord all that night.

1 Samuel 15:29

15:29 The Preeminent One ¹  of Israel does not go back on his word ²  or change his mind, for he is not a human being who changes his mind.” ³ 

[15:29]  ¹ tn Heb “splendor,” used here by metonymy as a title for the Lord.

[15:29]  ² tn Or perhaps “does not lie.”

[15:29]  ³ sn This observation marks the preceding statement (v. 28) as an unconditional, unalterable decree. When God makes such a decree he will not alter it or change his mind. This does not mean that God never deviates from his stated intentions or changes his mind. On the contrary, several passages describe him as changing his mind. In fact, his willingness to do so is one of his fundamental divine attributes (see Joel 2:13; Jonah 4:2). For a fuller discussion see R. B. Chisholm, Jr., “Does God Change His Mind?” BSac 152 (1995): 387-99.