1 Samuel 15:11 and God Changing His Mind

• Does God change his mind in 1 Samuel 15:11?
• How can you reconcile 1 Samuel 15:11 and Numbers 23:19?

1 Samuel 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.

Numbers 23:19 — 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?