The pursuit continued as far as Aijalon. When it stopped, the exhausted people flew upon the cattle and sheep and ate them with the blood, a ritual sin (Genesis 9:4 *, Leviticus 17:10-12 *), at which Saul was greatly distressed; he was evidently punctilious as to religious observances. He had a great stone set up as an altar, and had the animals for food slain in proper sacrificial fashion.
1 Samuel 14:31-35
31 And they smote the Philistines that day from Michmash to Aijalon: and the people were very faint.
32 And the people flew upon the spoil, and took sheep, and oxen, and calves, and slew them on the ground: and the people did eat them with the blood.
33 Then they told Saul, saying, Behold, the people sin against the LORD, in that they eat with the blood. And he said, Ye have transgressed:h roll a great stone unto me this day.
34 And Saul said, Disperse yourselves among the people, and say unto them, Bring me hither every man his ox, and every man his sheep, and slay them here, and eat; and sin not against the LORD in eating with the blood. And all the people brought every man his ox with himi that night, and slew them there.
35 And Saul built an altar unto the LORD: the same was the first altar that he built unto the LORD.