Netakim [diseased patches on the head or beard] make impure after two weeks [maximum] and through two signs: Thin yellow hair or spreading. Thin yellow hair [means] diseased and short. [These are] the words of Rabbi Akiva. Rabbi Yochanan ben Nuri says: Even if long. Rabbi Yochanan ben Nuri said: What does the phrase that they say [mean], "This stick is thin" [or] "This reed is thin?" [Does it mean] thin, diseased and short or thin, diseased and long? Rabbi Akiva said to him: Before we learn from the stick, let us learn from the hair. [If one says,] "The hair of so-and-so is thin," [he means] "Thin, diseased and short," not "Thin, diseased and long."

Thin yellow hair makes impure [whether it is] concentrated or spread out, [entirely] surrounded [by the Netek] or not [entirely] surrounded, changed [to yellow by the Netek] or not changed. These are the words of Rabbi Yehuda. Rabbi Shimon says: It only makes impure if changed [by the Netek]. Rabbi Shimon said: And this is logical; just as white hair, from which another [non-white] hair does not save [his purity status], only makes impure if changed [by the Netek], thin yellow hair, from which another [non-yellow] hair does save [his purity status], is it not logical that it should only make impure if changed?! Rabbi Yehuda says: Anywhere [in the Torah] where it should say [it needs to be] changed, it said [it needs to be] changed. But the Netek, of which it is said, (Leviticus 13:32) "It did not have in it yellow hair," makes him impure whether changed or not changed.

[A Netek] that sprouts [normal hair] saves him from the [impurity caused by] yellow hair or expansion, [whether it is] concentrated or scattered, [entirely] surrounded [by the Netek] or not [entirely] surrounded. And the remaining [normal hair, which preexists the Netek,] saves him from [impurity caused by] yellow hair or from expansion, [whether it is] concentrated or scattered, or [entirely] surrounded. But it does not save when on the edge [of the Netek] unless it is a distance of two hairs from the upright [normal hairs surrounding the Netek]. One yellow [hair] and one black [hair, which preexist the Netek], [or] one yellow and one white, do not save [him from impurity].

Yellow hair that preexisted the Netek is pure. Rabbi Yehuda declares impure. Rabbi Eliezer ben Yaakov says: It does not make impure, but it does not save [from impurity]. Rabbi Shimon says: Anything that is not a sign of impurity in the Netek is surely a sign of purity in the Netek!

How does one shave the Netek [during the second week of quarantine]? He shaves outside of it and leaves two [normal] hairs adjacent to it, so that it will be recognizable if it expands. If [the priest] decided [the Netek was impure] through yellow hair, [and then] the yellow hair went away and [then] the golden hair returned, and so too with expansion, [whether this happened] initially, at the end of the first week, at the end of the second week, or after the exemption [that made the Netek pure], [the Netek] is like it was [i.e. it is impure]. If [the priest] decided [the Netek was impure] through expansion, [and then] the expansion went away and [then] the expansion returned, so too with yellow hair, [whether this happened] at the end of the first week, at the end of the second week, or after the exemption [that made the Netek pure], [the Netek] is like it was [i.e. it is impure].

Two Netakim, one beside the other, and a row of [normal] hair separates between them, [if the row] is broken in one place, he is impure. In two places, he is [still] pure. How [wide] is a breakage? The area of two hairs. [If] it was broken in one place [even the size of] a bean, he is impure.

Two Netakim, one inside the other, and a row of hair separates between them, [if the row] is broken in one place, he is impure. In two places, he is pure. How [wide] is a breakage? The area of two hairs. [If] it was broken in one place [the size of] a bean, he is pure.

Someone who had a Netek with yellow hair in it, it is impure. If he develops black hair [in the Netek], he is pure. Even if the black hair goes away, he is [still] pure. Rabbi Shimon ben Yehuda says in the name of Rabbi Shimon: Any Netek that was pure at one time, never again has impurity. Rabbi Shimon says: Any yellow hair that was pure at one time, never again has impurity.

Someone who had a Netek like [the size of] a bean and [then] his entire head was [covered by the] Netek, he is pure. The head and the beard do not stop each other [from making him pure if one of them is entirely covered but the other is not]. These are the words of Rabbi Yehuda. Rabbi Shimon says: They do stop each other [if one is not fully covered]. Rabbi Shimon said: And this is logical; just as the skin of the face and the skin of the flesh, which have something else [i.e. a beard] separating between them, stop each other [if one is not fully covered], the head and the beard, which do not have something else separating between them, is it not logical that they should stop each other?! The head and the beard do not combine with each other [to constitute the minimum area required for impurity] and cannot expand from one to the other. What is [considered] the beard? From the joint of the jawbone to the thyroid cartilage.

The Karachat [blemish that balds the back of the head] or Gabachat [blemish that balds the top of the head] are made impure after two weeks [maximum], and through two signs: a healthy patch of skin or an expansion. What is [the source of] Karachat? [If] he eats a balding medicine, [or] he anointed with a balding medicine, [or] a [head] wound that is not able to grow hair. What is [the location of] Karachat? From the crown sloping backward until the cartilage of the neck. What is [the location of] Gabachat? From the crown sloping forward until the upper hair[line]. Karachat and Gabachat do not combine with each other [to constitute the minimum area required for impurity] and cannot expand from one to the other. Rabbi Yehuda says: If there is hair between them, they do not combine. But if not, surely they combine.