It’s Not SexistBy Rabbi Jack Abramowitz
The zav discharge described in the previous aliyah is not semen. If a man has a seminal discharge, he must immerse in a mikvah and he will be unclean until nightfall. Any garment that gets semen on it must likewise be immersed and will be considered unclean until nighttime. When a couple has sex and the man emits semen (as is typically the case) both of them must immerse in a mikvah and they will be unclean until sundown. (You may be aware that nowadays we do not generally act this way, as this is a form of ritual impurity that has no practical application in our day and age. We don’t have a Temple and we don’t have sanctified food, so there is no ramification to remaining in this state of ritual impurity. This is in contradistinction to niddus – menstrual impurity – which has a huge ramification, as we shall see. There are communities, however, where men are accustomed to regularly use the mikvah.)
When a woman has her period – or discharges any blood from her uterus – she will be considered ritually unclean for seven days; she will transmit a degree of uncleanliness to others, who immerse in a mikvah and remain in this status until night. As with a zav, touching her bed or sitting where she sat is sufficient to transmit this impurity to a person and his clothes. If a man has sex with a woman in the state of niddus (which is forbidden, as we will see in next week’s portion, Acharei Mos), he will be unclean for a week and his bed will transmit impurity, just like hers.
If a woman experiences a flow between periods, she is what’s called a zavah, as opposed to a niddah. Her bed and the things she sits on have the same status as they do during her period. When the discharge finishes, she must wait seven days, then immerse in a mikvah.