1) FASTING ON "TISH'AH B'AV" DURING THE TIME OF THE SECOND BEIS HA'MIKDASH
QUESTION: The Beraisa quotes Rebbi Elazar b'Rebbi Tzadok who relates that it once happened that Tish'ah b'Av occurred on Shabbos and the fast was deferred to Sunday, the tenth of Av, which was his family's personal Yom Tov, the day of his "Korban Etzim." When the second Beis ha'Mikdash was built, his forebears donated wood to the Beis ha'Mikdash, and in recognition for that Mitzvah they were granted the privilege of bringing wood to the Beis ha'Mikdash every year on the tenth of Av (as described in Nechemyah 10:35, and Ta'anis 26a). Since that day was his family's personal Yom Tov, they started the fast but did not complete it.
Rebbi Elazar b'Rebbi Tzadok presumably lived at the time of the Churban, as we find that his father, Rebbi Tzadok, was one of the elders at the time of the Churban (Gitin 57b). When, then, did this incident occur -- before or after the Churban? If it occurred during the time of the Beis ha'Mikdash (as he donated wood to the Beis ha'Mikdash on the tenth of Av each year), then why was the rest of the nation fasting on Tish'ah b'Av? If, on the other hand, it occurred after the Churban, then why did he celebrate a Yom Tov on the day of his Korban Etzim?
(a) TOSFOS in Ta'anis (12a, DH Hasam) writes that it is evident from the fact that Rebbi Elazar b'Rebbi Tzadok fasted on Tish'ah b'Av that this incident occurred after the Churban. Tosfos understands, like the TASHBATZ (2:271), that the Jews did not fast on Tish'ah b'Av during the time of the second Beis ha'Mikdash.
RAV MOSHE STERNBUCH shlit'a proves from here that even after the Churban, they observed their families' personal Yom Tov in commemoration of the day on which their families used to bring the Korban Etzim during the times of the Beis ha'Mikdash (see MO'ADIM U'ZEMANIM 7:212).
(b) The RAMBAM (Perush ha'Mishnayos to Rosh Hashanah 1:3) has a novel approach. He maintains that even during the time of the second Beis ha'Mikdash, the people fasted on Tish'ah b'Av, during the time that the Jews no longer had dominion in their land. According to the Rambam, it is possible that the incident of Rebbi Elazar b'Rebbi Tzadok occurred during the time of the Beis ha'Mikdash.
2) HALACHAH: A FAST THAT OCCURS ON FRIDAY
OPINIONS: The Gemara discusses whether or not a fast that occurs on Friday is observed in its entirety. Does one fast the entire day until the onset of Shabbos at nightfall, or should one eat before the end of the fast in order not to enter Shabbos in a state of hunger? The Gemara concludes that one completes the entire fast. What is the Halachah?
(a) TOSFOS RABEINU PERETZ and other Rishonim explain that the Gemara does not mean that one is obligated to fast the entire day on Friday. Rather, it means that one is permitted to fast the entire day. However, l'Chatchilah, it is better to eat before Shabbos begins.
Tosfos Rabeinu Peretz relates that the RI indeed ate on the fast of the Tenth of Teves when it occurred on Friday (the Tenth of Teves is the only fast that can occur on Friday according to our fixed calendar). The TUR (OC 249) cites this opinion as well.
(b) The RAN in Ta'anis (7a) writes that one is not permitted to eat before Shabbos begins when the Tenth of Teves occurs on Friday. The Gedolei Ashkenaz also ruled that one is not allowed to eat on a fast day that falls on Friday until the fast is over.
(c) The MAHARIL compromises and rules that on a public fast day, a person should be stringent and not eat until the fast is over. On an individual's private fast day, however, one is permitted to eat before the fast is over in order not to enter Shabbos in a state of hunger.
The REMA (OC 249) rules in accordance with the Maharil.
3) HALACHAH: RELIEVING ONESELF IN PUBLIC
OPINIONS: Rabah rules that one who walked beyond his Techum of 2000 Amos and thereby became restricted to an area of four Amos may leave his four Amos in order to relieve himself. This is because Kavod ha'Beriyos, human dignity, overrides the commandment not to disobey the Rabanan. The Gemara adds that one who is clever will take advantage of being permitted to go beyond the four Amos and walk all the way back to his Techum.
In what situation does the allowance to leave one's four Amos in order to go to the bathroom apply?
(a) The ROSH cites RABEINU YEHUDAH BARCELONI who maintains that the Gemara's allowance to leave one's four Amos does not apply to one who merely needs to urinate. It applies only to one who needs to defecate. He bases his ruling on the Gemara in Bechoros (44b) which says that "people urinate in public." Since people are not embarrassed to urinate in public, there is no concern for Kavod ha'Beriyos and he may not leave his four Amos. (This reasoning would not apply to a woman who is confined to her four Amos, since it is never acceptable for a woman to urinate in public.)
The Rosh concurs with Rabeinu Yehudah Barceloni and concludes that the allowance to leave one's four Amos does not apply to one who needs to urinate. (Even though his four Amos will become soiled with his urine, that is not sufficient reason to allow him to move, since the urine soon becomes absorbed into the ground and dries. However, the ARUCH HA'SHULCHAN writes that if he needs to recite Shemoneh Esreh or Birkas ha'Mazon and the urine has not yet dried, he may leave his four Amos.)
(b) RAV HAI GA'ON, cited by Rabeinu Yehudah Barceloni in the Rosh, suggests that the concern for Kavod ha'Beriyos does not refer to the person who needs to relieve himself. Rather, it refers to the people who will see him doing so. It is embarrassing and disgraceful for others to see him urinating, and therefore he may leave his four Amos.
HALACHAH: The SHULCHAN ARUCH (OC 406) cites both opinions with regard to leaving one's four Amos in order to urinate. The MISHNAH BERURAH (406:9) writes that one should follow the more stringent opinion (and not leave his four Amos in order to urinate).
Regarding how far one may walk in order to relieve himself, the Rosh rules that when the Gemara says that once he leaves his four Amos in order to find a place to relieve himself, he may walk all the way back to his city and reclaim his Techum, this refers only to when he does not find a bathroom before he reaches his city. If he finds a bathroom or other private place before he reaches his city, he must relieve himself there and he may not continue walking to his city. The Gemara's intention is that one who needs to find a bathroom should walk in the direction of his city, and not in any other direction, and if he does not find a bathroom before he reaches his city, then he may reclaim his Techum.
The Rosh adds that even if he finds a private area in which to relieve himself before he reaches his city, he may leave those four Amos if the smell is intolerable and continue walking until the smell ends; if he happens to walk as far as his city, then he may reclaim his Techum. This is the Halachah as recorded by the SHULCHAN ARUCH (OC 406).