Why does the Pasuk insert "Zos ha'Torah ... "?
Seforno: To teach us that whoever comes to Pasken the Dinim of Nega'im, must be able to distinguish between two kinds of Nega'im, even if they belong to the same category - such as the difference between Nega Tzara'as and Nesakim (both on a person's skin), 1 as the Torah goes on to explain. 2
Sifra: "Zos ha'Torah le'Chol Nega Tzara'as ve'la'Nasek ... " teaches us that a Kohen who is not conversant in all areas of Tzara'as
The latter are Tamei by the hair falling out, whereas the former require one of the four appearances (Refer to 13:30:1:1*).
And by the same token, he must be able to distinguish between Tzara'as on a garment and Tzara'as on a room, even though both are supernatural and both occur by means of a deep red or deep yellow mark on the skin - if the Nega spreads after the first week, the former is obligated to replace the stones and the mortar ... , whereas the latter is Tamei and must be burnt. And by the same token again, he must be able to distinguish between a Se'es, a Sapachas and a Baheres, even though they all occur by a white mark on the skin and are examined for the same signs and they even combine, the examiner must be able to distinguish between the different shades of white and their locations (as the Torah explains in Pasuk 55 and 56, bearing in mind that a Nega on the location of a boil and a burn can combine, whereas a scar on the same location and on the location of hair is not examined for an appearance at all (Seforno).
Why does the Torah place "ve'la'Tzara'as ha'Beged ve'la'Bayis" in the middle of Nig'ei Adam?
Sifra: To teach us that Nig'ei Begadim, 1 like Nig'ei Batim, are Metamei be'Bi'ah. They are not require birds for their purification however, since the Torah writes "Zos" to preclude them.
See ha'Torah ve'ha'Mitzvah, Siman 180.
Seeing as (in Pasuk 56) the Pasuk mentions Se'eis Sapachas and Baheres , what is "le'Chol 'Nega Tzara'as" referring to?
Ramban: It refers to Tzara'as Sh'chin and Michvah. 1
Seforno: Refer to 14:54:1:1**.
With which the Pasuk begins - because they are the most common forms of Tzara'as on the skin (Ramban).
