1 Samuel 15:35
“And Samuel came no more to see Saul until the day of his death: nevertheless Samuel mourned for Saul: and the Lord repented that he had made Saul king over Israel.”
And Samuel said, As thy sword hath made women childless, so shall thy mother be childless among women. And Samuel hewed Agag in pieces before the Lord in Gilgal.
Then Samuel went to Ramah; and Saul went up to his house to Gibeah of Saul.
And Samuel came no more to see Saul until the day of his death: nevertheless Samuel mourned for Saul: and the Lord repented that he had made Saul king over Israel.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“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.”
“And he stripped off his clothes also, and prophesied before Samuel in like manner, and lay down naked all that day and all that night. Wherefore they say, Is Saul also among the prophets?”
“And the Lord said unto Samuel, How long wilt thou mourn for Saul, seeing I have rejected him from reigning over Israel? fill thine horn with oil, and go, I will send thee to Jesse the Beth–lehemite: for I have provided me a king among his sons.”
“And lest, when I come again, my God will humble me among you, and that I shall bewail many which have sinned already, and have not repented of the uncleanness and fornication and lasciviousness which they have committed.”
“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.”