Two and twenty thousand If the particular numbers mentioned (Numbers 3:22; Numbers 3:28; Num 3:34) be put together, they make twenty-two thousand three hundred. But the odd three hundred are omitted here, either according to the use of the Holy Scripture, where in so great numbers small ones are commonly neglected, or because they were the firstborn of the Levites, and therefore belonged to God already, and so could not be given to him again instead of the other firstborn. If this number of firstborn seem small to come from twenty-two thousand Levites, it must be considered, that only such firstborn 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.,) with the number of this from a month old; and therefore it is not strange if the number of their firstborn 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.