20 And if you should gather your olives, you shall not return to collect the remainder; it shall be for the stranger, and the fatherless, and the widow, and you shall remember that you were a slave in the land of Egypt; therefore I command you to do this thing.
Deuteronomy 24:20 Cross References - CAB
Leviticus 19:10
10 And you shall not go over the gathering of your vineyard, neither shall you gather the remaining grapes of your vineyard: you shall leave them for the poor and the stranger: I am the Lord your God.