Shabbat 65B

פסולות לכהונה.

are disqualified from marrying into the priesthood. The act renders a woman a zona. It is prohibited for a priest to marry her (Tosafot).

לא ⁠— סבר כי היכי דלא לילפן גופא נוכראה.

The Talmud rejects this: No, that is not necessarily so. Perhaps the reason for Shmuel’s father’s insistence was because he thought to prevent them from lying next to one another so that they would not become accustomed to sleeping with a foreign body, which could stimulate sexual desire.

ועביד להו מקוה ביומי ניסן, מסייע ליה לרב, דאמר רב: מטרא במערבא סהדא רבה פרת. סבר, שלא ירבו הנוטפין על הזוחלין.

And he made a mikveh for them in the days of Nisan. This supports the opinion of Rav, as Rav said: When rain falls in the West, Eretz Yisrael, the great witness attesting to that fact is the Euphrates, as the water flow in the Euphrates increases after the winter. The rainfall in northern Babylonia, where the source of the Euphrates is located, is essentially parallel to the rainfall in Eretz Yisrael. The increased water flow of the Euphrates in the spring is the result of the rainfall in the winter. Shmuel’s father held that immersion in the Euphrates would not purify them. A river maintains its status as a river in terms of purification through immersion only if it is established that the rain water that fell would not exceed the naturally flowing spring water. In the halakhot of ritual baths, there are two manners of purification. The first is the immersion in a place where water is gathered, e.g., collected rainwater that does not flow and remains in place. The second is immersion in flowing waters in their natural state, e.g., a spring or a river. However, rainwater purifies only when it is collected; it does not purify when it is flowing.