Numbers 1:44

These [are] those that were numbered
Or, as the Targum of Jonathan, these are the sums of the numbers; namely, those before given of the several respective tribes:

which Moses and Aaron numbered, and the princes of Israel, [being]
twelve men;
for though the tribe of Levi was not numbered, yet Joseph having a double portion, his two sons are reckoned as distinct tribes; so that one out of each tribe made up the number twelve:

each one for the house of his fathers;
for the tribe he belonged to, with which it might reasonably be supposed he was best acquainted, and could more readily take the number of them.