Numbers 31:27

And divide the prey into two parts
Into two equal parts, both the number of the people and of the cattle, when taken:

between them that took the war upon them, and went out to battle;
the soldiers; and by this it appears that they went voluntarily and cheerfully:

and between all the congregation;
so that the part of them that went to battle, and of those that stayed in the camp, were alike, and which in process of time became a statute and ordinance, ( 1 Samuel 30:24 1 Samuel 30:25 ) ( Psalms 68:12 ) .