The blood of a niddah [a female who has menstrual discharges which render her impure] and the flesh of a corpse render impurity when damp, and render impurity when dry. But the discharge [of a zav, a male who has certain types of atypical genital discharges which render him impure], and the phlegm [of a zav], and the spit [of a zav], and a [dead] vermin, and carrion, and semen render impurity when damp but do not render impurity when dry. If they can be steeped [in water] and thereby revert to their original condition, they render impurity when wet and render impurity when dry. And how long must they be steeped? In lukewarm water, from a time to that time [twenty four hours later]. Rabbi Yose says: the dry flesh of a corpse, if it cannot be steeped and thereby reverted to its original condition, is pure.

A [dead] vermin found in an alleyway retroactively renders impure [anything that was in the alleyway, until the time it was found and] since such a time regarding which one says, "I examined this alleyway and there was no vermin in it," or since the hour at which it was [last] cleaned. Similarly regarding a [blood] stain found on a [woman's] robe, it retroactively renders impure [any pure items which the woman handled, until the time the stain was found and] since such a time regarding which one says, "I examined this robe and there was no stain on it," or since the hour it was [last] washed. And it [i.e. the vermin or the stain, retroactively] renders impurity, whether it is damp or dry. Rabbi Shimon says: if it is dry it renders impurity retroactively, but if it is wet it renders impurity only since the hour at which one could go back and it would be damp [i.e. regarding the vermin, the hour at which, if it had fallen then or later, it could still be damp currently].

All [blood] stains that come from Rekem [an area on the Eastern border of Israel] are pure [i.e. since the Jews there are assumed to be careful to hide their niddah stains, such stains are assumed to be from gentiles and therefore pure]. Rabbi Yehuda regards them as impure, because they [the inhabitants] are converts who are in error [i.e. and thus their blood is impure since they are Jews, and since they suspected of not being careful to hide their blood, their stains are impure for they may be from a niddah]. Those [bloodstains] that come from among the gentiles are pure. [Those that come] from among Israelites or from among the Samaritans, Rabbi Meir regards them as impure, and the Sages regard them as pure, for they are not suspected with regard to [failing to hide their] their stains [i.e. therefore any stains found can be assumed not to have come from a niddah].

All [blood] stains found anywhere are pure, except those found in rooms or in the area around a house of impurities [i.e. a house used by impure women]. A Samaritan house of impurities renders impurity by overshadowing because they bury the stillborn there. Rabbi Yehudah says: they would not bury them, but rather they would toss them out, and animals would drag them [away].

They [the Sameritans] are trusted when they say, "we buried the stillborn there," or "we did not bury [them there]." They are trusted when they say, regarding an animal, whether it has given birth to its firstborn or has not yet given birth. They are trusted regarding the marking of graves. But they are not trusted regarding [the locations of graves under] overhanging branches or protrusions [of wood or stone in a fence, when there is an uncertainty as to the location of a grave in their proximity], nor regarding a beit hapras [a field in which a grave has been plowed over, which may or may not contain a corpse]. This is the general rule: regarding a matter about which they are suspected [of not keeping], they are not trusted about it.