1 Chronicles 10:13

13 So death came to Saul because of the sin which he did against the Lord, that is, because of the word of the Lord which he kept not; and because he went for directions to one who had an evil spirit,

1 Chronicles 10:13 Meaning and Commentary

1 Chronicles 10:13

So Saul died for his transgression
(See Gill on 1 Samuel 31:13) A violent and dishonourable death, which was suffered on account of the sins he was guilty of:

one was, which he committed against the Lord, even against the word of
the Lord, which he kept not;
both in not staying for Samuel the time appointed, and by sparing the Amalekites whom he was bid to destroy, ( 1 Samuel 13:13 1 Samuel 13:14 ) ( 1 Samuel 15:3 1 Samuel 15:9 )

and also for asking counsel of one that had a familiar spirit, to
inquire of it;
what he should do with respect to engaging in battle with the Philistines, ( 1 Samuel 28:8 1 Samuel 28:15 ) which to do was contrary to an express command of God, ( Leviticus 19:31 ) .

1 Chronicles 10:13 In-Context

11 And when the news came to Jabesh-gilead of what the Philistines had done to Saul,

12 All the fighting-men came up and took away Saul's body and the bodies of his sons, and took them to Jabesh, and put their bones to rest under the oak-tree in Jabesh, and took no food for seven days.

13 So death came to Saul because of the sin which he did against the Lord, that is, because of the word of the Lord which he kept not; and because he went for directions to one who had an evil spirit,

14 And not to the Lord: for this reason, he put him to death and gave the kingdom to David, the son of Jesse.