Numbers 18:21

And, behold, I have given the children of Levi all the tenth
in Israel for an inheritance
The tenth part of the produce of the land; of the wheat, barley, oil, and wine; the tenth part of their harvest and vintage; so that though they were the least of the tribes, they had the greatest share of the increase of the land, and that without any labour or expense; the other having but nine parts among them all, and at the charge and labour of manuring, cultivating and this they were to have

for their service which they serve, even the service of the tabernacle
of the congregation;
see ( Numbers 18:3-6 ) .