Numbers 9:6

And there were certain men who were defiled by the dead body of a man,.... The Targum of Jonathan adds,"who died by them suddenly,''whereby pollution was contracted, see Nu 6:9; though perhaps this was a whole house or family, one of which was dead, and so all were defiled, being in the place where the dead body was, or had touched it, or been concerned however in the burying of it, and on account of which were unclean seven days, and so might not eat of any holy things, as the passover; and though at the first institution there was no such law, yet since that time there was, which obliged them, see Le 7:20; and it is said , that the section concerning the red heifer, and so of defilement by a dead body, was delivered on the day the tabernacle was erected, even on the first day of the first month; and though recorded in Nu 19:1; yet was given out before this; and indeed otherwise it is not easy to conceive how these men should know that the dead body of a man was defiling:that they could not keep the passover on that day; as others did, the fourteenth of Nisan, it being, according to the Targum of Jonathan, the seventh day of their defilement:and they came before Moses, and before Aaron, on that day; on the selfsame day the passover was kept, and they were sensible of their pollution, which disqualified for it; and therefore it should rather seem to be the first day of their pollution than their last; since otherwise they would doubtless have inquired about this matter before the passover came; unless the time of their pollution was so near out, that they thought they might eat it safely, on which they desired advice.