1 Samuel 30:23-25

23But David said, “You must not do so, my brothers, with what the Lord has given us, for He has protected us and handed over to us the band of raiders that came against us. 24And who will listen to you in this matter? For 1as is the share of the one who goes down into the battle, so shall be the share of the one who stays by the baggage; they shall share alike.” 25So it has been from that day forward, that he made it a statute and an ordinance for Israel to this day.