Divrey Hayamim Alef 10:13

13 So Sha’ul died for his ma’al (unfaithfulness) which he committed against Hashem, even against the Devar Hashem, over which he was not shomer, and also for consulting an ov (one with a familiar spirit) to seek guidance;

Divrey Hayamim Alef 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 ) .

Divrey Hayamim Alef 10:13 In-Context

11 And when kol Yavesh Gilead heard all that the Pelishtim had done to Sha’ul,

12 They arose, kol ish chayil, and took the gufat Sha’ul (body of Sha’ul), and the gufot of his banim, and brought them to Yavesh, and buried their atzmot under the elah (oak tree) in Yavesh, and underwent a tzom shivat yamim.

13 So Sha’ul died for his ma’al (unfaithfulness) which he committed against Hashem, even against the Devar Hashem, over which he was not shomer, and also for consulting an ov (one with a familiar spirit) to seek guidance;

14 And inquired not of Hashem; therefore He slaughtered him, and turned over the kingdom unto Dovid Ben Yishai.