This week's Parsha (12:1-8) describes one of the few mitzvos applicable
exclusively to women. A woman who has given birth is required to bring a
korban before being permitted to touch Kodesh or enter the Mikdash. The
korban is brought 40 days after the birth of a boy and 80 days after the
birth of a girl. The reason for this mitzva is that during the pangs of
childbirth a woman is likely to have impulsively vowed to refrain from
further relations with her husband. Niddah 31b. (Note that in any event a
vow of this type would not be legally binding, see Kli Yakar.)
The Sforno on 12:8 presents a different reason for this korban. He says
that during the entire post-partum period of 40/80 days the woman has
necessarily been pre-occupied with and focused on matters relating to the
workings of the reproductive organs. It is not appropriate for her to
enter the Mikdash in this lingering state of mind. The korban therefore
serves to re-focus her attention away from the post-partum period and
prepares her to once again turn toward the Mikdash.
The Sforno's insight affords a deeper understanding of the last pasuk of
Parshas Yisro (20:23) where the pasuk requires that a ramp, and not steps,
is to be used by the Kohanim to ascend the mizbeyach. The reason for this
is given by the pasuk as 'asher lo sigoleh ervascha alav', meaning so
that 'your ervah' not be revealed.
Rashi on this pasuk in Yisro explains that because Kohanim wear
michnosayim (pants) there would not be bona fide ervah revealed in any
event. Rather, utilizing steps would require longer strides to be taken,
and taking longer strides is akin to ervah being revealed. How does
taking long strides lead to ervah being revealed, bona fide or not?
Based upon the Sforno in Tazria, this Rashi can be explained as meaning
that, physically, a man ascending stairs (as opposed to a ramp) will have
no choice but to separate one leg from the other by some meaningful
distance, thereby presenting moments of potential focus on ervah. The
basic idea, both in Tazria and in Yisro, is that the Mikdash is no place
for focus on ervah, no matter how subtle.