1 Samuel 14:32-33

32So the army rushed greedily on the plunder, confiscating sheep, cattle, and calves. They slaughtered them right on the ground, and the army ate them blood and all.

33Now it was reported to Saul, “Look, the army is sinning against the Lord by eating even the blood.” He said, “All of you have broken the covenant! Roll a large stone over here to me.”