Seeing as all appearances of white appear lower than the skin, what does the Torah mean when it writes "ve'Amok Ein Mar'ehu min ha'Or"?
Rashi: is baffled by this statement.
Ramban: The Baheres only appears deeper than the skin when white or yellow hairs appears in it, but not when the hairs are black. 1
Seforno: It is speaking where the skin is also more white than usual.
Rashbam: It is speaking where the Nega is less white than any of the four Mar'os Nega'im that render him a Metzora. 2
Targum Yonasan: It is speaking where the Nega is white like lime (the Toldah of Baheres) but not like the Baheres itself. 3
What is the point in locking up the Tzar'ua?
Rashi: By locking him up in one location and not seeing the Nega for a week, any change will show up clearly when the Kohen sees him the next time.