The Gemara on our daf seeks the reasons behind the various enactments listed in that Mishna in Zavim.
- Washing with drawn water after going to the mikvah
The fourth enactment states that one who washes his head and the greater part of his body with drawn water, after he was tovel correctly and was now tahor, becomes tamei.
The reason for this was that originally people who were tamei would immerse themselves in pools of cave water that were stagnant, which did make them tahor. However, after the immersion, they would then pour over themselves clean water that was drawn from vessels in order to wash away the dirty water.
Eventually people mistakenly started to say that it was the drawn water that purified them, not the cave water.
The Sages were then concerned that those who are tamei would immerse in drawn water alone, which is not a kosher mikvah. To discourage this, the Rabbis decreed that one who washes his head and the greater part of his body with drawn water, after he was tovel, becomes tamei.
- Sefer Torah, Neveim, and Kesuvim make terumah passul
The sixth enactment was that a Sefer Torah, a Neveim, and a Kesuvim, will make terumah which it touches passul.
Rav Mesharshia explains that the reason for this was that people used to store their Sefer Torah[O1] , Neveim, and Kesuvim together with their terumah, reasoning it was appropriate because both are holy.
The Rabbonim saw that this practice resulted in the Sefarim becoming damaged by mice that were attracted to the food. They therefore decreed that the scrolls would make terumah passul in order that people would not store their terumah near them.
- Netilas Yadaim instituted three times
The seventh enactment was that if one’s hands touch terumah, the terumah becomes passul, (and therefore one is required to wash his hands before touching terumah).
In fact, Netilas Yadayim (washing of the hands) was instituted at three separate times:
a.Shlomo Hamelech instituted that unrinsed hands were considered tamei when touching Kodshim. They were regarded though as tahor when it came to touching terumah. This was the first time that washing one’s hands before touching terumah was enacted.
b.Hillel and Shamai decreed that unrinsed hands were considered tamei when touching terumah as well, but their decree was not accepted.
c.Lastly, in the upper chamber of Chananya ben Chizkiyah ben Garon, the students of Hillel and Shamai argued about the status of one’s hands in regards to terumah. Beis Shamai held that unwashed hands should be considered tamei for terumah and require washing, while Beis Hillel disagreed. When the vote was held, Beis Shamai being the majority, prevailed.
