Two and twenty thousand — If the particular numbers mentioned Numbers 3:22, Numbers 3:28, Numbers 3:34, be put together, they make 22,300. But the odd 300 are omitted here, either according to the use of the holy scripture, where in so great numbers small sums are commonly neglected, or, because they were the first — born of the Levites, and therefore belonged to God already, and so could not be given to him again instead of the other first — born. If this number of first — born seem small to come from 22,000 Levites, it must be considered, that only such first — born are here named as were males, and such as continued in their parents families, not such as had erected new families of their own. Add to this, that God so ordered things by his wise providence for divers weighty reasons, that this tribe should be much the least of all the tribes, as is evident by comparing the numbers of the other tribes, from twenty years old, Numbers 1:3-49, with the number of this from a month old; and therefore it is not strange if the number of their first — born be less than in other tribes.
Related Commentaries of Numbers 3:39
Numbers 3:39
39 All that were numbered of the Levites, which Moses and Aaron numbered at the commandment of the LORD, throughout their families, all the males from a month old and upward, were twenty and two thousand.