We have learned that although a nazir cannot allow himself to become tameh met, not all situations of tum’at met automatically undo the efforts of the nazir. In some cases a nazir may become tameh met, yet he will simply resume his nezirut after he completes the purification process. In the Mishna on our daf , Rabbi Eliezer quotes Rabbi Yehoshua as teaching that only those situations of tum’at met that are severe enough to undo nezirut will be considered severe enough to make someone liable for entering the Temple precincts in a state of tum’ah.
The discussion of the Gemara focuses on a technical point. Was the source of this teaching really Rabbi Yehoshua, or, perhaps, was it Rabbi Yehoshua bar Memel, which is the implication of a number of the sources? The Gemara’s conclusion is that when the tradition is passed on by three people (or more), only the first and last of the teachers must be named specifically; the middle names can be left out.
To support this statement, Rav Naḥman bar Yitzḥak presents a teaching from Nahum ha-Lavlar regarding a question of how pe’a must be given in a situation where several different crops are planted in a single field. This law is quoted in the name of Rabbi Mi’asha who received the teaching from his father, who received the teaching from the zugot – the pairs of early tannaim listed in Massekhet Avot – who received the teaching from the prophets, who received it as an oral tradition from Mount Sinai (halakha le-Moshe mi-Sinai). In this list of rabbinic scholars, the names of Moshe and Calev are left out, indicating that as long as the first and last teachers are mentioned by name, some of the middle names can be left out.
The expectation that Moshe and Calev would be included stems from the above-mentioned Mishna that introduces Pirkei Avot: Moshe received the Torah from Mount Sinai, passing it to Yehoshua, Yehoshua to the Elders – of whom Calev was the first – the Elders to the prophets, who passed it on to the Anshei Knesset haGedolah.