Leviticus 11:31

“These are unclean to you of all that creep, etc.] Unfit for food, and not to be touched, at least when dead, as in the next clause, that is, these eight sorts of creeping things before mentioned, as the Targum of Jonathan expresses it, and these only, as Maimonides says f399: whosoever doth touch them when they are dead shall be unclean until the even; for touching them while alive did not defile, only when dead; and this the Jews interpret, while they are in the case in which they died, that is, while they are moist; for, as Ben Gersom says, if they are so dry, as that they cannot return to their moisture, they do not defile; for which reason, neither the bones, nor nails, nor nerves, nor…”

“whosoever doth touch them, when . . . dead, shall be unclean until the even--These regulations must have often caused annoyance by suddenly requiring the exclusion of people from society, as well as the ordinances of religion. Nevertheless they were extremely useful and salutary, especially as enforcing attention to cleanliness. This is a matter of essential importance in the East, where venomous reptiles often creep into houses and are found lurking in boxes, vessels, or holes in the wall; and the carcass of one of them, or a dead mouse, mole, lizard, or other unclean animal, might be inadvertently touched by the hand, or fall on clothes, skin bottles, or any article of common domestic use.…”

“Lev 11:8, Lev 11:24, Lev 11:25 Leviticus 11:32”