Explanation: R. Nechemyah's reason is because the matter that the Kesem is on is Tahor, also regarding the woman [Chachamim] did not decree.

Implied question: In the case of Mashtisa (a frame with threads arranged for weaving) below [R. Yanai ruled that if when she walks, the frame passes under the place, she is Teme'ah, even though it is not Mekabel Tum'ah]!

Answer: Granted, it is not Mekabel other Tum'ah, but it is Mekabel Tum'as Tzara'as.

Explanation (Rashi): We attribute that perhaps she felt, but did not put it to her mind.

Objection #1 (and Explanation #2): Even if she is Muchzak that she did not feel, she is Temei'ah, since she saw Dam Nidah!

Objection #2: Also Rav Ashi agrees that according to Shmuel, when she did not feel, she is Tehorah mid'Oraisa and Temei'ah mid'Rabanan! [Rav Ashi] just comes to explain that when [blood] is found on the ground, she is Tehorah even mid'Rabanan.

Question: What was the question? Surely we do not establish Tum'ah from place to place to be lenient, but to be stringent, like here, we are stringent [to do so]!

It says below that we do not simulate (an episode that occurred) to be lenient, but to be stringent, we simulate!

Answer: Since Kesamim are mid'Rabanan, if it were true that we attribute to be stringent, we would attribute also to be lenient, on something somewhat common;

However, from place to place, which is not so common, we say below that even regarding Kesamim, we simulate to be stringent, but to be lenient.

Question: We should ask from our Mishnah! Not in line with the place [from which Dam Nidah leaves], she is Tehorah. We do not say that she checked with this hand, and touched her skin above the place!

Answer: Had she checked herself and found that she is Temei'ah, she would remember. She would put it to her mind that she is Temei'ah;

However, when she touched blood on her shoulder, she does not put it to her mind, since this blood is not Tamei.

Below, regarding Tamei blood, [the Gemara] asks "say that she checked with this hand, and touched the other [hand on the knuckles]!", we ask based on a Kal v'Chomer. (Even regarding Tamei blood, which she puts to her mind, we attribute from place to place. All the more so we should say so regarding Tahor blood!)

Observation: We could have asked [against the Beraisa] also from our Mishnah [which is Metaher above the place. We are not concerned that she checked with her hand, and touched above the place]!

Assertion: We can distinguish between "from place to place" here and above (4a). There, the Tum'ah itself comes from place to place. Here, the Tum'ah itself stays in one place. (Blood is Metamei her only when it leaves her Makor. If it is found elsewhere, it merely arouses concern that it came from her Makor.)

Explanation #1 (Rashi): This is where the thigh joins the shin. Chavak is where the sinews stretch to clamp the thigh to the lower leg.

Explanation #2 (Aruch): They wear socks with [garter] loops. The place where the loops attach is called Chavak.

Explanation #3 (Aruch): One bends the shin on the thigh. The flesh that is covered through bending the shin on the thigh, that they press on each other is called Chavak.

Explanation (Ri): These are drops. If k'Shurah were connected, this would be a strip discussed below;

"Many drops' discussed below is when they are jumbled, not in a circle and not in a line.

Implied question: It says below that many drops do not join! (Here it connotes that if they came from the place, they join!)

Answer: That is when they are on a garment. Here we discuss on her skin. There is more reason to attribute to blood of a louse when they are on a garment that when they are on her skin.

Question: Also monetarily, the second should be obligated to launder it, like it says in Kesuvos (76b) the one in whose Reshus the Safek arose, he must bring a proof!

Answer #1: Since the second only borrowed it, it is not truly in her Reshus.

Answer #2: It says there that if he wants to make the other pay, he must bring a proof. Here, the latter is not obligated to launder it [since the lender cannot bring a proof].

Question: What is the comparison to the case above? Here, we cannot attribute to one more than to the other. However, above we cannot attribute to the first, since she checked!

Answer (R. Tam): The Beraisa discusses when they engaged in a bird, one after the other. Had the first asked, we would have been Metaher her, since she engaged. Due to her friend, we are Metamei the first, who was totally Tehorah;

Also above, even though the first checked, we should be Metamei her, since the second may attribute [the Kesem] to her monetarily.

Implied question: Why didn't he say "any sheet", like below (regarding Chachamim's opinion)?

Answer: Here we need to say bed, for even [the bed of] a man has many drops of blood [that must be] of lice. If so, also on a woman's [bed], we should attribute to a louse;

Below, we discuss only a woman's. Therefore, it mentioned a sheet (i.e. with which she checks herself).

Distinction: However, when she killed many lice or a Pishpesh (bedbug), she attributes according to how many she killed, just like a butcher's market. (If she passed through, she attributes even a big Kesem to it, for much blood splashes.)

Explanation (Rashbam): [We are not concerned for Kesamim] even bigger than a bean, and even below the belt, and even if she did not engage, and she does not have a wound that could open and emit blood.

Pesak (Ri): One may not rely on this nowadays to be lenient when she finds Kesamim in a place where it is not common to touch pigs. This is the custom, not to attribute.

However, when there are Raglayim l'Davar to attribute to pigs and similar matters, we attribute, like the Gemara says.