[Concerning a woman who bleeds] in labor within eighty [days] of a female [birth], any blood that she discharges is tahor un-til the child is born. But R’ Eliezer declares it tamei. They said to R’ Eliezer: If even in a case where [the Torah] was stringent regarding blood [discharged during a period] of relief, it was lenient regarding the blood [discharged] in labor, [then] in a case where [the Torah] was lenient regarding blood [discharged during a period] of relief, is it not logical that we must be le-nient regarding the blood [discharged] in labor? [R’ Eliezer] replied: It is sufficient for the derived law to be [the same] as the source law: From what [tumah] did [the Torah] spare her? [It is] from the tumah of zivah, but she is tamei as a niddah.

[Throughout] all [the] eleven days [of potential zivah] [a woman] is presumed to be tahor. If she sat and did not examine herself, [whether it was] inadvertently, by mishap or deliberately that she failed to examine herself, she is tahor. [If] the time for her fixed period arrived and she did not examine herself, she is tamei. R’ Meir says: If she was in a hiding place and the time for her fixed period arrived and she did not examine herself, she is tahor, because terror suspends the [discharge of] bloods. However, [during] the days of a zav, a zavah and one who is observing a day [free of discharge] against the day [on which she discharged blood], they are presumed to be tamei.

[Concerning a child] who emerges [from its mother] through the [abdominal] wall, [the mother] does not observe on its ac-count the days of tumah and the days of taharah, and is not liable on its account to an offering. [But] R’ Shimon says: This [child] is like a [naturally] born child.  All women become contaminated [once their contaminating flow is] in the “outer room,” for it is stated: her discharge from her flesh being blood. But a zav and one who emitted semen do not become con-taminated until their tumah exits to the outside [of their bodies].

If [a Kohen] was eating terumah and he felt that his limbs were trembling, he grasps the male organ and he swallows the te-rumah.  [These discharges] contaminate in any amount, even [an amount] equal to a mustard seed and [even an amount] less than that.