Keep the rules which the Lord your God gave you

Pride against the orders of the Lord

And Samuel said to Saul, You have done a foolish thing: you have not kept the rules which the Lord your God gave you; it was the purpose of the Lord to make your authority over Israel safe for ever.
1 Samuel 13:13

1Sa 13:11 And Samuel said, What have you done? And Saul said, Because I saw that the people were going away from me, and you had not come at the time which had been fixed, and the Philistines had come together at Michmash;
1Sa 13:12 I said, Now the Philistines will come down on me at Gilgal, and I have made no prayer for help to the Lord: and so, forcing myself to do it, I made a burned offering.
1Sa 13:13 And Samuel said to Saul, You have done a foolish thing: you have not kept the rules which the Lord your God gave you; it was the purpose of the Lord to make your authority over Israel safe for ever.
1Sa 13:14 But now, your authority will not go on: the Lord, searching for a man who is pleasing to him in every way, has given him the place of ruler over his people, because you have not done what the Lord gave you orders to do.