Rambam - 1 Chapter a Day

An affliction whose external symptoms bear some resemblance to leprosy and hence, it is often mistranslated as such. Nevertheless, as the Rambam writes in Chapter 16, Halachah 10, unlike leprosy, the afflictions of tzara'at are not the result of a physical condition, but are the manifestation of spiritual blemishes.

I.e., the thin membrane surrounding the egg-white. It does not have to be as white as the egg-white itself or its shell.

With regard to the translation of the term bohak, R. Abraham Ibn Ezra (Leviticus 13:39) writes: “The meaning of this term was known to our Sages; there is no similar term found in Scripture.”

See Numbers 12:1 which speaks of Miriam being “afflicted with tzara’at like snow.”

The root of the term is the word bahir which means “clear” or “radiant.”

I.e., not the natural state of the wool, but after it has been washed [the Rambam’s Commentary to the Mishnah (Nega’im 1:1)].

I.e., when it has not yet been dirtied (ibid.).

The Ra’avad in his gloss to Halachah 6 and R. Abraham Ibn Ezra (commentary to Leviticus 13:2) state that the term si’ait relates to the concept of burning. Ramban cites Sh’vuot 6b which states that the term refers to something upraised.

As the Rambam mentions in the conclusion of this halachah, the term sapachat means an “addition” or “subsidiary.” Sh’vuot 6b mentions a similar use of the root in I Samuel 2:36 and Ibn Ezra cites a parallel in Isaiah 14:1.

I.e., the term sapachat implies a subsidiary category and can refer to a subsidiary of baheret or of si’ait.

Nega’im 1:1; Sh’vuot 1:1.

I.e., if a baheret blemish and a si’ait blemish are contiguous, they are not considered as two separate blemishes, but as a single entity, regardless of whether this leads to a more lenient ruling or a more stringent one.
The Ra’avad takes issue with the Rambam on this point, citing Sh’vuot 6a which states: “Should [a blemish that resembles] the lime of the Temple be combined with one that is si’aif? They are not of the same type.” Apparently, the Ra’avad concludes, only a primary category and its derivative can be combined.
The Kessef Mishneh notes that although Nega’im 1 :3 appears to imply that all four types of blemishes can be combined, Rabbenu Shimshon interprets that mishnah according to the Ra’avad’s conception: that only a primary category and its derivative can be combined. Nevertheless, he cites the Jerusalem Talmud (Sh’vuot 1:1) which understands the mishnah as the Rambam does. He does, however, cite a difficulty in the Rambam’s understanding, for the Babylonian Talmud (Sh’vuot, loc. cit.) speaks of a difference of a difference of opinion between Rabbi Akiva and the Sages and the Rambam appears to incorporate elements of both perspectives.

If the person’s entire body is covered with tzara’at—in which instance, he is considered pure (Chapter 7, Halachah 2)—that ruling is given even when the blemish is made up of several different hues of white.

To be combined to produce the minimum measure of a blemish.

See Chapter 9, Halachah 2, which states that the determination of the status of a tzara'at blemish is dependent on a priest. While it's true that a priest can depend on a sage for the determination and merely make the pronouncement himself, if he desires to rely on his own determination, he must study until he can recognize the different shades. See also Chapter 9, Halachah 1, and notes.

Sefer HaMitzvot (positive commandment 101) and Sefer HaChinuch (mitzvah 169) include the commandment to rule regarding the different shades of tzara’at as one of the 613 mitzvot of the Torah.

The Sifra explains that although this statement is made only with regard to baheret, since the prooftext states “It is tzara’at,” we can conclude that it applies to all other shades of tzara’at [the Rambam’s Commentary to the Mishnah (Nega’im 1:2)].

The term means “mixed,” in Aramaic; see the Targum of Yonason ben Uziel to Job 25:2.

The Ra’avad follows a different understanding of Sh’vuot 6b in which the levels of petuch are mentioned in the reverse order with the petuch of baheret having only two drops of blood. The Kessef Mishneh mentions the rationale for the Rambam’s view: Since baheret is the brightest white, the redness will not be apparent unless it is significant.

See the parallel in Chapter 14, Halachah 3.

This addition is made on the basis of the gloss of Kiryat Sefer who maintains that certainly a blemish that can be felt physically imparts impurity. The Rambam is emphasizing that even when that is not so, as long as the blemish appears to penetrate beneath the surface of the skin, it imparts impurity. For according to the Rambam, it makes no difference at all whether a blemish can be felt physically or not. There are others, however, who cite Bechorot 41a as indicating that if the blemish can be felt physically, it does not impart impurity.

I.e., when one looks at light and a shadow, the light appears to be further removed than the shadow (Siftei Chachamim to Leviticus 13:3).

The Rit’avad notes that the term si’ait has the connotation “upraised.” Hence, he maintains that although the qualification stated by the Rambam is mentioned in Leviticus 13:3, it is referring only to a baheret. The Kessef Mishneh justifies the Rambam’s position.

See Chapter 12, Halachah 1.

A gris is half a bean. Cilik is a place where beans grow very large [the Rambam's Commentary to the Mishnah (Keilim 1 7:1 12)]. Most contemporary experts consider this to be the size of an American dime.

Rav Kapach’s translation of the Rambarn’s Commentary to the Mishnah (Ma’aserot 5:8) states that the natural pattern of growth for these beans tends to squareness.

Note the following halachah which emphasizes that the intent is not the total area. In his Commentary to the Mishnah (Nega’im 6:1), the Rambam emphasizes that the intent is not that blemish must be square, but that it must be large enough to encompass a square of this size.

I.e., part of the Oral Tradition, without any explicit source in the Written Law.

Leviticus 13:3-12. These signs are discussed in detail in Chapters 2, 3, and 4 respectively.

More specifically 13 days, as stated in Chapter 9, Halachah 9. The Torah does not mention a longer process of examination than this.

I.e., it is not considered as a new baheret which requires examination again.

I.e., the intensity of its whiteness was reduced.

I.e., the shade of whiteness of the blemish increased or decreased, but not its size.

Which appears to imply that the darkening of the blemish is sufficient to have the person declared as pure. The Rambam felt it necessary to emphasize this point, because others (see Rashi’s commentary to the verse) understood the verse differently.