At the end of every three years, bring a tenth of all your produce for that year and lay it up within your gates.
28. At the end of three years. Those are mistaken, in my opinion, who think that another kind of tithe is here referred to. It is rather a correction or interpretation of the Law, lest the priests and Levites alone should consume all the tithes, without applying a part to the relief of the poor, of strangers, and widows.
We have here a part of the statute concerning tithes. The productions of the ground were twice tithed, so that, putting both together, a fifth part was devoted to God out of their increase, and only four parts of five were for their own common use; and they could not but own they paid an easy rent, especially since God's part was disposed of to their own benefit and advantage.
Commenting on Deuteronomy 14:22-29
At the end of three years . . . the Levite . . . shall come, &c.--The Levites having no inheritance like the other tribes, the Israelites were not to forget them, but honestly to tithe their increase [Num 18:24].