1 Chronicles 10:13

13 So Saul died for his unfaithfulness to the LORD, because he did not keep the word of the LORD and even consulted a medium for guidance,

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 When all the people of Jabesh-gilead heard about everything the Philistines had done to Saul,

12 all their men of valor set out and retrieved the bodies of Saul and his sons and brought them to Jabesh. And they buried their bones under the oak in Jabesh and fasted seven days.

13 So Saul died for his unfaithfulness to the LORD, because he did not keep the word of the LORD and even consulted a medium for guidance,

14 and he failed to inquire of the LORD. So the LORD put him to death and turned the kingdom over to David son of Jesse.