By the dead body of a man; by the touch of a dead body, or something belonging to it; \see Numbers 19:11\ because unclean persons were prohibited to eat of holy things. See Leviticus 8:20, Leviticus 22:3. They came before Moses, for resolution of their difficulty.
Related Commentaries of Numbers 9:6
Numbers 9:6
6 And there were certain men, who were defiled by the dead body of a man, that they could not keep the passover on that day: and they came before Moses and before Aaron on that day: