who stayed with the supplies is to be the same as that of him who went down to the battle. All will share alike

1 Samuel 30:18-31
David replied, “No, my brothers, you must not do that with what the Lord has given us. He has protected us and delivered into our hands the raiding party that came against us. Who will listen to what you say? The share of the man who stayed with the supplies is to be the same as that of him who went down to the battle. All will share alike.” David made this a statute and ordinance for Israel from that day to this.
David sent it to those who were in Bethel, Ramoth Negev, Jattir; and to those in all the other places where he and his men had roamed.
All is recovered. And Judah and the Calebites, also victims of the rai, share in the spoil.
Why?
The victory is by the grace of the Lord, so the man who stayed with the supplies is to be the same as that of him who went down to the battle.
David made a statute and ordinance for Israel and to Christians. 
Because it is the grace of the Lord, share the plunder as a gift to all other friends.
How?
Be generous is better than stingy. All I have is the grace of the Lord.
不如意事，不見得是不好，神安排讓大衛無法與非力士人出戰，同時隔天離開。讓大衛可以去救自己家人。
正當大衛的部下因為失去家人，本來以為可以依靠的王，卻變成不可靠，想用石頭攻擊大衛。大衛此刻求問神並且得著力量。大衛進入非力士人土地，前沒有問神，投靠亞吉也沒有求問神。這時他求告神。這是人的軟弱，人常常以為靠自己就可以了。神也還是接納我們，並沒有不理我們。
回到洗革拉，也是回到神面前。
大衛所屬的家人與財產居然沒有一人被殺害，這是神的保守。在當時，將被擄者殺害是很正常的事，更何況是以色列宿敵亞馬力人。
一般人對待別人像是使用器具，沒有用就丟掉了。這個埃及人生病就被丟棄。大衛沒有惡意對待敵人，提供食物和水，於是這個埃及人提供了極佳的情報，讓大衛可以很快找到家人。大衛對待已經疲憊的同袍也是充滿憐憫，否則可能一起去，反而造成傷亡。善意對待家人及敵人，可以化敵為友。成為助力。