Siman - Eruvin Daf 18
- פסין לביראות ובורות הרבים
On Daf 17b, the opening Mishnah of the second perek taught, עושין פסין לביראות – We may erect boards for wells to permit drawing water from them on Shabbos. Wells are a reshus hayachid, and therefore one cannot draw water from them into a reshus harabim. However, the Rabannon enacted a unique leniency that would permit people who were travelling up to Yerushalayim for the regalim to draw water from wells on Shabbos. By erecting boards around a well, the area within the boards are to be considered a reshus hayachid, thereby allowing to draw water into it.
The Gemara initially suggests that the Mishnah, which specifies the leniency to be applying to wells, does not go according to Rebbe Akiva who holds that פסין can also be used for בורות הרבים - public water holes (but not for a בור היחיד).
The Gemara concludes that the Mishnah also permits פסין around בורות הרבים. However, the Mishnah only wanted to teach the case of wells because, באר מים חיים דפסיקא ליה – the law for the case of a well, which has spring water, is clear cut. Meaning, it makes no difference whether the well is public or private. The Mishnah did not want to teach the law for בורות, which differs between public and private ones since in the case of a public water hole, people will remind each other not to carry if it dries up, whereas an individual might not remember.
- דיומדין
When the Mishnah stated we may erect boards for wells to permit drawing water from them on Shabbos, it says to use דיומדין. The Gemara asks what are דיומדין, and Rebbe Yirmiyah ben Elazar said דיומדין means double posts. The prefix דיו means two, and it is attached to the word עמוד which means post. He also teaches, דיו פרצוף פנים היה לו לאדם הראשון - Adam Harishon was created with two faces, as it says in the passuk, אחור וקדם צרתני – From the front and back you have formed me. The Gemara continues with the machlokes regarding the creation of Chava, which we learned in Berachos Daf 61a.
- מקצת שבחו של אדם בפניו
Six of eight teachings of Rebbe Yirmiyah ben Elazar are taught on this Daf. Among them is, מקצת שבחו של אדם אומרים בפניו – Part of a person’s praise one may mention in his presence, וכולו שלא בפניו – but all of it only in his absence. This is learned from the parsha of Noach, where Hakadosh Baruch Hu praised Noach partially when He spoke to him directly as it says, כי אתך ראיתי צדיק לפני בדור הזה – For it is you I have seen to be righteous before Me in this generation, whereas in Noach’s absence He said, נח איש צדיק תמים היה בדורותיו – Noach was a righteous man, perfect in His generation.
