Introduction Mishnah three contains a dispute between Hillel and Shammai with regards to the laws of the mikveh (ritual bath).
Hillel says: “A hin full of drawn water renders the mikweh unfit.” (However, man must speak in the language of his teacher.) And Shammai says: “Nine kavs.” But the Sages say: “Neither according to the opinion of this one nor according to the opinion of this one;” But when two weavers from the dung-gate which is in Jerusalem came and testified in the name of Shemaiah and Avtalion, “Three logs of drawn water render the mikweh unfit,” the Sages confirmed their statement. A mikveh, a ritual bath used to cleanse ritual impurity, must contain water that has not been drawn by human hands. The water must get into the mikveh by natural means, either through rain or a stream. The question our mishnah asks is how much drawn water can fall into a mikveh before it becomes unfit to cleanse? According to Hillel, if one hin falls in, the mikveh is unfit. A hin is equal to three kavs (about 4 ½ liters). The mishnah notes that Hillel used the word “hin” and not the word “kav”, even though kav is more commonly used and Hillel himself used the word in the previous mishnah. The answer is that Hillel heard this law about the mikveh from his teacher in this language, and although Hillel himself did not regularly use this language he still taught the statement in the form that he heard it. This is to teach that when you quote your teacher you must use the same language s/he used. Shammai gives a larger measure which would make a mikveh unfit: nine kavs. A smaller amount of drawn water that falls into a mikveh does not render it unfit. As we saw in the first two mishnayoth, the Sages accept neither the words of Shammai nor the words of Hillel. Rather they accept the testimony given by two weavers who were at the Dung-Gate in Jerusalem (the gate next to the Western Wall), who said that Shemaiah and Avtalion, two early Sages, stated that three lugs, which is a quarter of a hin, are enough to render the mikveh unfit.