Unclean - If the due purification was omitted at the time, through negligence or forgetfulness, a sin-offering was required. See Leviticus 5:2.
Related Commentaries of Leviticus 11:24
Leviticus 11:24-28
24 And for these ye shall be unclean: whosoever toucheth the carcase of them shall be unclean until the even.
25 And whosoever beareth ought of the carcase of them shall wash his clothes, and be unclean until the even.
26 The carcases of every beast which divideth the hoof, and is not clovenfooted, nor cheweth the cud, are unclean unto you: every one that toucheth them shall be unclean.
27 And whatsoever goeth upon his paws, among all manner of beasts that go on all four, those are unclean unto you: whoso toucheth their carcase shall be unclean until the even.
28 And he that beareth the carcase of them shall wash his clothes, and be unclean until the even: they are unclean unto you.