Q. Mishneh Torah relates that the kohen removes the kupah from the head of the women in the Laws of Sota 3:9  and that she is not wearing a redidh or mitpahath; yet Numbers 5:18 says “…and he exposes the woman’s head” (Num. 5:18) when it describes the kohen removing the kupah from her head. Doesn't this prove that her head isn't regarded as exposed (paruwa), even if her neck is showing, as is the case when only wearing a kupah?
A. First of all, the Torah passage at hand mentions neither the word redidh, mitpahath, or kupah, so the question assumes a false premise. The text of the Torah does not indicate what head-garment must be removed in order that the woman’s head be regarded as exposed (paruwa’).
However, at whatever point her head is to be regarded as exposed (paruwa), Numbers 5:18 shows that her head is made "paruwa" even before the administering of the oath that is mentioned in Numbers 5:19. Hil. Sota 3:5-10 explains that the woman is administered the oath even though she is still wearing a kupah; but Hil. Sota 3:5 informs us that her redidh and mitpahath were already removed; so I don't know what Numbers 5 can prove, other than that her head is already regarded as exposed (paruwa) even though she still wears a kupah, being that the oath is administered before the kupah is removed, as Hil. Sota 5 explains. If anything, this indicates that her head is already regarded as exposed (paruwa) while wearing only the kupah. This is in harmony with Hil. Ishuth 24:11 which states that the woman's head is regarded as exposed (paruwa) if she is not wearing a redidh, even though her hair is covered in a mitpahath. Needless to say, this indicates that the redidh covers more than just the hair.
(Laws of Suspect Women) Hilkhoth Sota 3:5-10
(Laws of Women) Hilkhoth Ishuth 24:11
* DorDeah.com is an independent organization. DorDeah.com is not affiliated with www.mechon-mamre.org, the "Torath Moshe Society," nor Chabad-Lubavitch. Though we are grateful for the contributions of these organizations in providing Mishne Torah resources, we do not endorse all the views espoused by these organizations.