1 Samuel 30:21-25

21David came to the two hundred men who were so exhausted that they could not follow him and had been left at the brook Besor [with the provisions]. They went out to meet David and the people with him, and when he approached the people, he greeted them.

22Then all the wicked and worthless men among those who went with David said, “Because they did not go with us, we will give them none of the spoil that we have recovered, except that each man may take his wife and children away and leave.”

23David said, “You must not do so, my brothers, with what the Lord has given us. He has kept us safe and has handed over to us the band [of Amalekites] that came against us.

24And who will listen to you in regard to this matter? For as is the share of him who goes down into the battle, so shall his share be who stays by the provisions and supplies; they shall share alike.”

25So from that day forward he made it a statute and an ordinance for Israel to this day.