Leviticus 23:21-22

And you shall proclaim on the same day that it is a holy convocation to you. You shall do no customary work on it. It shall be a statute forever in all your dwellings throughout your generations. ‘When you reap the harvest of your land, you shall not wholly reap the corners of your field when you reap, nor shall you gather any gleaning from your harvest. You shall leave them for the poor and for the stranger: I am the LORD your God.’ ”