And inquired not of the LORD: therefore he slew him, and turned the kingdom unto David the son of Jesse.

Wesley's Notes

10:14 Enquired not - He did in some sort, but not in a right manner, not humbly and penitently, not diligently and importunately, not patiently and perseveringly. Nor 'till he was brought to the last extremity. And then it was too late.

King James Translators' Notes

Jesse: Heb. Isai

Jamieson-Fausset-Brown Bible Commentary

14. And inquired not of the Lord-He had done so in form (1Sa 28:6), but not in the spirit of a humble penitent, nor with the believing confidence of a sincere worshipper. His enquiry was, in fact, a mere mockery, and his total want of all right religious impressions was manifested by his rushing from God to a wretched impostor in the service of the devil [1Sa 28:7].

Matthew Henry's Concise Commentary

10:1-14 The death of Saul. - The design chiefly in view in these books of the Chronicles, appears to be to preserve the records of the house of David. Therefore the writer repeats not the history of Saul's reign, but only of his death, by which a way was made for David to the throne. And from the ruin of Saul, we may learn, 1. That the sin of sinners will certainly find them out, sooner or later; Saul died for his transgression. 2. That no man's greatness can exempt him from the judgments of God. 3. Disobedience is a killing thing. Saul died for not keeping the word of the Lord. May be delivered from unbelief, impatience, and despair. By waiting on the Lord we shall obtain a kingdom that cannot be moved.