Numbers 18:21: “Behold, I have given the children of Levi all the tithes in Israel as an inheritance in return for the work which they perform, the work of the tabernacle of meeting.”
The assignment of “all the tithes in Israel” to the Levites appears to be something new and is not found, in contrast to the priestly provisions, in the Levitical legislation. Tithing was an ancient institution, antedating the Mosaic law by centuries. The regulation here laid down clearly has reference to Israel’s future settlement in Canaan, when in a settled agricultural economy the tithing of the produce of the land would become possible. Here again, as with the priests in the previous verses, the twofold point is made that the tithe was a payment both as a return for service and a recognition of the dangers involved in their responsibilities, on the one hand, and on the other as a compensation from the Lord for their lack of territorial inheritance.
The modern church has claimed the tithe as her own, refusing to admit that the priests portion is only one tenth of the basic tithe.