Self-Evident?
‘What Uncleanness Is There In A Nasal Discharge?’
(Niddah 55b-56a)
The mishnah on 54b lists spittle as one of the bodily secretions of a zav that convey tumah. This ruling is based on Vayikra 15:8: “Ve’chi yarok hazav batahor ve’chibes begadav ve’rachatz ba’mayim ve’tamei ad ha’arev – And if the zav spit upon someone, that person shall immerse his garments and immerse himself in the water, and he remains unclean until the evening.” A baraisa (55b) states that the term “if the zav spit” includes other secretions as well such as mei ha’af.
What is “mei ha’af”? Shmuel says it denotes discharges from the nose or mouth. Nasal secretions are no different than saliva, he argues.
Rav, on the other hand, asserts that nasal secretions are not like saliva and do not convey tumah. He maintains that “mei ha’af” means phlegm expelled through the mouth, which conveys tumah because it is impossible to discharge phlegm through the mouth without traces of saliva attaching themselves to it.
Two Questions
The commentators ask two compelling questions:
1) Why, according to Rav, must the baraisa derive the uncleanness of “mei ha’af” from “if the zav spit”? Since we already know that saliva of a zav is unclean and since we know the phlegm expelled from the mouth contains particles of saliva, it should be self-evident that phlegm is unclean. (The Aruch LaNer asks this question.)
2) Why should the small amount of saliva mixed in with the phlegm be of any significance? Since the saliva comprises only a small percentage of the total mixture, it should be nullified in the majority (batal b’rov). (The Be’er Avraham [Hilchos Metam’ei U’Moshav 1:14] asks this question.)
Simple Logic
The Marcheshes (37:1-10) writes that these questions present no difficulty at all. Indeed, they each provide the answer for the other one. The Marcheshes explains that if not for “if the zav spit,” a zav’s phlegm wouldn’t be tamei since only traces of saliva are in it and these traces would be batal b’rov.
Why then, does Rav say that it’s impossible to discharge phlegm through the mouth without traces of saliva? Why is that relevant? Because it explains why expelled phlegm should be treated more stringently than a nasal discharge. But, indeed, if not for “if the zav spit,” the miniscule amount of saliva would be considered halachically nullified.