When you reap the harvest of your land, you are not to reap to the very edges of your field or gather the gleanings of your harvest.

Leviticus 19:8
Whoever eats it will bear his iniquity, for he has profaned what is holy to the LORD. That person must be cut off from his people.

Leviticus 19:10
You must not strip your vineyard bare or gather its fallen grapes. Leave them for the poor and the foreigner. I am the LORD your God.

Leviticus 23:22
When you reap the harvest of your land, do not reap all the way to the edges of your field or gather the gleanings of your harvest. Leave them for the poor and the foreign resident. I am the LORD your God.'"

Deuteronomy 24:19
If you are harvesting in your field and forget a sheaf there, do not go back to get it. It is to be left for the foreigner, the fatherless, and the widow, so that the LORD your God may bless you in all the work of your hands.

Deuteronomy 24:20
When you beat the olives from your trees, you must not go over the branches again. What remains will be for the foreigner, the fatherless, and the widow.

Ruth 2:2
And Ruth the Moabitess said to Naomi, "Please let me go into the fields and glean heads of grain after someone in whose sight I may find favor." "Go ahead, my daughter," Naomi replied.

And when you reap the harvest of your land, you shall not wholly reap the corners of your field, neither shall you gather the gleanings of your harvest.