When you reap your harvest in your field and forget a sheaf in the field, you shall not go back to get it; it shall be left for the alien, the orphan, and the widow, so that the Lord your God may bless you in all your undertakings.  When you beat your olive trees, do not strip what is left; it shall be for the alien, the orphan, and the widow.  When you gather the grapes of your vineyard, do not glean what is left; it shall be for the alien, the orphan, and the widow.  Remember that you were a slave in the land of Egypt; therefore I am commanding you to do this.
 

“For remember that you were once slaves in Egypt; that is why I command you to observe this rule.”

The people are commanded to be charitable and not miserly; to not horde but in all things share, for they are liberated slaves and they must remember that by doing these things.

We too have been liberated – by the blood of Christ.  Remembrance, therefore, is critical to the Christian.  We lose sight of who we are when we are miserly.  Therefore we are commanded to love our neighbor.  To share the goods – material and spiritual – we have been given, so that we may remember who we are: children of the Father who belong to him, who are returning to him, and to whom we must render an account in love and justice.