lie with another man beneath a single garment.
The Prophet’s words, “A woman must not look at the private parts of another woman,” are a clear prohibition directed at the onlooker, forbidding her to gaze at the private parts of the one being seen. That is, if the woman being observed happens to have her private parts uncovered by a gust of wind, while relieving herself, or for some similar reason, it is unlawful for the other woman to look at them. In this context, the private parts are the area between the navel and the knee.
Likewise, if a man’s private parts are exposed because of the wind or for any other reason, it is impermissible for another man to look at them.
Some women have cited this hadith as proof that a woman is only obliged to cover what lies between her navel and her knee. This is a misunderstanding, for the Prophet (peace and blessings be upon him) did not grant a woman permission to wear a garment that covers only that region; rather, he forbade the other woman from looking at it should it be exposed. The difference between the two matters is obvious.
A woman who is clothed must wear a garment that conceals her body. The women of the Companions—may Allah be pleased with them—used to cover everything from the top of the foot to the wrist of the hand; all of that was kept hidden. Yet if, out of necessity or because of a gust of wind or the like, a woman’s private area becomes exposed, the other woman must not look at what lies between her navel and her knee. The same ruling applies to men: a man is not permitted to look at another man’s private parts.