Siman - Eruvin Daf 21
- Why well must be a באר מים חיים if just for animals
A Baraisa on Daf 20b states that פסי ביראות only permits animals (of the עולי רגלים) to drink from a well. A person, however, מטפס ועולה מטפס ויורד – must climb up and climb down into the well to drink there, as he is not permitted to carry the water within the enclosure of the פסין.
The Gemara asks that if פסי ביראות only permit animals to drink from a well, why was it said in the name of Shmuel that פסי ביראות only permits drawing water, לבאר מים חיים - from a well of spring water? If the פסין are only for animals, what difference does it make if the water comes from a well of running water or of collected water? The Gemara answers, בעינן מידי דחזי לאדם – we need something that is fit for human consumption. Rashi explains that since it is by virtue of the water that the boards become valid mechitzos, we need superior water, meaning water which is fit for human consumption.
- The Torah's vastness
Rav Chisda said in the name of Mari bar Mar about the passuk, לכל תכלה ראיתי קץ רחבה מצותך מאד – To every goal I have seen a limit, but Your commandment, (i.e. the Torah), is exceedingly broad, that the concept of the vastness of the Torah was mentioned by Dovid Hamelech, Iyov and Yechezkel, but they did not define it. It was only Zechariah ben Iddo who defined it.
Zechariah had a vision of a folded scroll that was twenty amos long with a width of ten amos. It was written on both sides, so when unfolded it would be forty amos by twenty amos, which is eight hundred square amos. A passuk from Yeshaya indicates that the entire universe is only a zeres, which is one quarter of a divine amah, which means that the Torah is 3,200 times greater than the size of the universe.
- Why Rebbe Akiva used water for washing instead of drinking
To illustrate the importance of Rabbinic law, the Gemara brings an incident when Rebbe Akiva was old and imprisoned and Rebbe Yehoshua ben Garsi would bring him water daily. One day, half of the water was spilled out by the guard, and Rebbe Akiva used the remaining water to wash his hands before eating instead of drinking it. When asked why he did so, Rebbe Akiva answered that it is better that I cause my own death caused by not drinking enough than I transgress a de’Rabbanon which carries the death penalty.
Rav Yehudah said in the name of Shmuel that when Shlomo Hamelech established the laws of eruv and netilas yadaim, a bas kol proclaimed, בני אם חכם לבך ישמח לבי גם אני – My son, if your heart is wise, My heart shall rejoice too.
