"At the end of [every] three years, bring a tenth of all your produce for that year and store [it] within your gates.
Deuteronomy 14:28 In-Context
Use the silver to buy whatever you like: cattle, sheep, wine or other fermented drink, or anything you wish. Then you and your household shall eat there in the presence of the LORD your God and rejoice.
And do not neglect the Levites living in your towns, for they have no allotment or inheritance of their own.
At the end of every three years, bring all the tithes of that year’s produce and store it in your towns,
so that the Levites (who have no allotment or inheritance of their own) and the foreigners, the fatherless and the widows who live in your towns may come and eat and be satisfied, and so that the LORD your God may bless you in all the work of your hands.