John Gill Commentary Numbers 18:11

"And this is thine: the heave-offering of their gift, even all the wave-offerings of the children of Israel; I have given them unto thee, and to thy sons and to thy daughters with thee, as a portion for ever; every one that is clean in thy house shall eat thereof." — Numbers 18:11 (ASV)

And this [is] thine What follow, which appertained to the priests, are the less or lighter holy things: the heave offering of their gift :

the right shoulder, given to the priest for an heave offering of the sacrifices of peace offerings, (Leviticus 7:32) ; according to Jarchi, it was what was lifted up or heaved from the thank offering, the peace offerings, and the ram of the Nazarites, see (Leviticus 7:14Leviticus 7:32) (Numbers 6:19Numbers 6:20) ;

with all the wave offerings of the children of Israel ;

which were waved to and fro before the Lord, as the breast of the peace offerings, called therefore the wave breast, (Leviticus 7:30Leviticus 7:34) ;

I have given them unto thee, and to your sons, and to your daughters with thee, by a statute for ever ;

for these were to be eaten in their own houses, and by their families, wives, children, and servants bought with their money, or born in their houses; but not hired servants, nor sojourners, nor strangers; nor their daughters married to strangers though, if widows, or divorced, and without children, and returned to their father's house, they might eat of them, (Leviticus 22:10–13) ;

thus a provision was made for the maintenance of the priests of the Lord and their families, until the Messiah should come; who has also appointed that they that preach the Gospel should live of it, (1 Corinthians 9:13 1 Corinthians 9:14) ;

everyone that is clean in your house shall eat of it : that was clean in a ceremonial sense; had not touched a dead body Jarchi says, this is said to comprehend his wife; but that might be concluded from what is said before, for if his children, much more might his wife eat of it.