Mi Yodeya is a question and answer site for those who base their lives on Jewish law and tradition and anyone interested in learning more. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

To the best of my knowledge there is a principle that if a woman knows with reasonable certainty ( or even reasonable suspicion ) that an emission of blood is from a wound and not from the uterus then she is not rendered niddah. This comes up often for instance in the case of gynaecological exams that can cause non-uterine bleeding.

If this is the case, then why would a woman be rendered niddah ( or safeq zavah or whatever you want to call it ) after defloration considering that we know with certainty that the blood is from the broken hymen.

share|improve this question
It's Rabbinic . – Double AA Oct 3 '13 at 20:03
@DoubleAA Could you expand on that a bit, be a bit more specific? – Robert S. Barnes Oct 3 '13 at 20:23
@RobertS.Barnes, in this particular instance, it is a rabbinic decree, since she experiences certain sensations that also might mask the sensation of a flow, just as the blood seen might mask the Dam Niddah, as might the seminal emission (if no blood is visible). – Seth J Oct 3 '13 at 20:36
up vote 8 down vote accepted

The source of this exception from dam makkah is a mishna on Niddah 64b, and the gemara on Niddah 65b.

There's a big machloket in the Rishonim about the reason why we have this exception to the general rule that blood from a wound is not niddah blood. I don't know them all of the top of my head, and I recommend The Laws and Concepts of Niddah by Rabbi Zvi Sobolofsky for a full treatment.

The reason we poskin by is that it's a rabbinic decree, enacted because she might emit niddah blood at the same time, and not be aware of it.

share|improve this answer
In English Niddah 64b halakhah.com/niddah/niddah_64.html#64b and Niddah 65b halakhah.com/niddah/niddah_65.html#65b – Robert S. Barnes Jun 29 '14 at 9:02

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.