1 Samuel 13:10-12

And it came to pass, that as soon as he had made an end of offering the burnt offering, behold, Samuel came; and Saul went out to meet him, that he might salute him. And Samuel said, What hast thou done? And Saul said, Because I saw that the people were scattered from me, and that thou camest not within the days appointed, and that the Philistines gathered themselves together at Michmash; therefore said I, The Philistines will come down now upon me to Gilgal, and I have not made supplication unto the LORD: I forced myself therefore, and offered a burnt offering.