1 Samuel 11:10-11

10They said to the Ammonites, “Tomorrow we will surrender to you, and you can do to us whatever you like.”

11The next day Saul separated his men into three divisions; during the last watch of the night they broke into the camp of the Ammonites and slaughtered them until the heat of the day. Those who survived were scattered, so that no two of them were left together.