I Samuel 13:11-13 NKJV
And Samuel said, “What have you done?”
Saul said, “When I saw that the people were scattered from me, and that you did not come within the days appointed, and that the Philistines gathered together at Michmash, then I said, ‘The Philistines will now come down on me at Gilgal, and I have not made supplication to the LORD.’ Therefore I felt compelled, and offered a burnt offering.”
And Samuel said to Saul, “You have done foolishly. You have not kept the commandment of the LORD your God, which He commanded you. For now the LORD would have established your kingdom over Israel forever.
NKJV: New King James Version