Above the zav [is] a zavah, in that she transmits tumah to any man who cohabits with her. Above the zavah [is] a metzora, in that he transmits tumah via entry [into a covered area]. Above the metzora [is] a bone the size of a barley grain, in that it transmits a tumah of seven [days]. More stringent than all of them [is] a corpse, in that it transmits tumah via an ohel, a means through which all the others do not transmit tumah.

Ten [levels of] tumah emanate from a person: A mechussar kippurim is forbidden [with regard] to kodesh but he is permitted [with regard] to terumah and maaser. [If] he subsequently became a tevul yom, he is forbidden [with regard] to kodesh and terumah but he is permitted [with regard] to maaser. [If] he subsequently became a baal keri, he is forbidden [with regard] to the three of them. [If] he subsequently became a bo’el niddah, he transmits tumah to a bed which is beneath him like that which is above. [If] he subsequently became a zav who experienced two discharges, he transmits tumah to a mishkav and a moshav, and he requires immersion in spring water, but he is exempt from an offering. [But if] he experienced three [discharges], he is obligated to bring an offering. [If] he subsequently became a confined metzora, he transmits tumah via entry [into a covered area], but he is exempt from letting his hair grow wild, from rending his garments, from shaving, and from the birds. But if he was a confirmed [metzora], he is obligated in all of these. [If] a limb was severed from him that does not have sufficient flesh on it, it transmits tumah via contact and via being carried, but it does not transmit tumah via an ohel. If it does have sufficient flesh on it, it transmits tumah via contact, via being carried, and via an ohel. The amount of flesh deemed sufficient is enough to effect healing. R’ Yehudah says: If in one place there is enough [flesh] to surround it with [the width of] a weft thread, it is enough to effect healing.