Deuteronomy 14:28-29

14:28 At the end of every three years you must bring all the tithe of your produce, in that very year, and you must store it up in your villages. 14:29 Then the Levites (because they have no allotment or inheritance with you), the resident foreigners, the orphans, and the widows of your villages may come and eat their fill so that the Lord your God may bless you in all the work you do.