1 Samuel 14:32-35

32[When night came and the oath ended] the people rushed greedily upon the spoil. They took sheep, oxen, and calves, and slaughtered them on the ground; and they ate them [raw] with the blood [still in them].

33Then Saul was told, “Look, the people are sinning against the Lord by eating [the meat] with the blood.” And he said, “You have violated [the Law] and acted treacherously; roll a large stone to me today.”

34Saul said, “Spread out among the people and tell them, ‘Each one of you bring me his ox or his sheep, and butcher it [properly] here and eat; and do not sin against the Lord by eating [the meat with] the blood.’ ” So that night each one brought his ox with him and butchered it there.

35And Saul built an altar to the Lord; it was the first altar that he built to the Lord.