Unclean - If the due purification was omitted at the time, through negligence or forgetfulness, a sin-offering was required. See Leviticus 5:2.

And for these ye shalt be unclean,.... That is, for eating them; or should they eat them they would be unclean:
whosoever toucheth the carcass of them shall be unclean until the even; not only he was unclean that ate them, but he that even touched their dead bodies was reckoned unclean; might not go into the tabernacle, nor have conversation with men, nor eat of the holy things, which were forbid men in any uncleanness; and though there is no mention of his washing himself, it may be understood, this being a short or concise way of speaking, as Aben Ezra observes; who adds, that it was necessary that he should wash himself in water; which was typical of washing and cleansing by the grace and blood of Christ, without which a man cannot be cleansed from the least sin, and pollution by it; and may signify that during the legal dispensation there was no proper cleansing from sin, until the evening of the world, when Christ came and shed his blood for the cleansing of it.

In Leviticus 11:24-28 there follow still further and more precise instructions, concerning defilement through contact with the carcases (i.e., the carrion) of the animals already mentioned. These instructions relate first of all (Leviticus 11:24 and Leviticus 11:25) to aquatic and winged animals, which were not to be eaten because they were unclean (the expression "for these" in Leviticus 11:24 relates to them); and then (Leviticus 11:26-28) to quadrupeds, both cattle that have not the hoof thoroughly divided and do not ruminate (Leviticus 11:26), and animals that go upon their hands, i.e., upon paws, and have no hoofs, such as cats, dogs, bears, etc.

Unclean - And such were excluded both from the court of God's house, and from free conversation with other men.