1 Samuel 8:7
And the LORD said to Samuel, Listen to the voice of the people in all that they say to you: for they have not rejected you, but they have rejected me, that I should not reign over them.
Torrey's Topical Textbook—AKJV

1 Samuel 15:23
For rebellion is as the sin of witchcraft, and stubbornness is as iniquity and idolatry. Because you have rejected the word of the LORD, he has also rejected you from being king.
Torrey's Topical Textbook—AKJV