1 Samuel 13:11-12

I saw that thou camest not When the seventh day was come, and a good part of it was past, I concluded thou wouldst not come that day. I have not made supplication Hence it appears that sacrifices were accompanied with solemn prayers. I forced myself I did it against my own mind and inclination: I offered a burnt-offering lest my enemies should attack me before I had commended myself and my cause to God, and entreated his aid and blessing.