Numbers 7:2

That the princes of Israel
The princes of the twelve tribes of Israel:

heads of the house of their fathers;
of the each of the houses and families the tribes were divided into, and took their name from each of their ancestors, as is next explained:

who were princes of the tribes;
the twelve tribes, as before observed, ( Numbers 1:4-16 ) ;

and were over them that were numbered;
over the children of Israel that were numbered, ( Numbers 1:19-46 ) ; by which it that these princes are the very same persons that are mentioned by name there, as they are here afterwards; and were with Moses and Aaron, and assisting to them when they took the number of them; but according to the Targum of Jonathan, and Jarchi, these were appointed over them in Egypt; but the former is right: these now

offered
not sacrifices but gifts; they brought their presents to the Lord for the service of his sanctuary, and set them before him, as follows.