Parashas Metzora · Passuk 15:26
Chabad.org — English translation + Rashi
Torah Temima points to Toras Kohanim.
English: “Like the impurity of her niddah” — like the impurity of her niddah, and not like the days of her niddah.
Impurity parallel, not day-count parallel
Chazal equate the zavah’s midras impurity to that of a niddah, but do not equate the length of the impurity period to the seven niddah days in every case.