Leviticus 19:10

19:10 You must not pick your vineyard bare, and you must not gather up the fallen grapes of your vineyard. You must leave them for the poor and the foreigner. I am the Lord your God.

Leviticus 25:5

25:5 You must not gather in the aftergrowth of your harvest and you must not pick the grapes of your unpruned vines; the land must have a year of complete rest.