1 Samuel 13:10-12

10And 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.

11And 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 assembled themselves together at Michmash;

12therefore said I, Now will the Philistines come down upon me to Gilgal, and I have not entreated the favour of the LORD: I forced myself therefore, and offered the burnt offering.