1) HALACHAH: WHEN IS THE PROPER TIME FOR MINCHAH?
OPINIONS: In the Mishnah (26a), Rebbi Yehudah and the Rabanan argue about the proper time to recite Minchah. The Rabanan maintain that one may recite Minchah until the end of the day. Rebbi Yehudah says that one may recite Minchah only until Plag ha'Minchah. The Gemara concludes that "d'Avad k'Mar Avad, d'Avad k'Mar Avad"; one may choose either opinion and abide by it. There are three approaches in the Rishonim as to what this means.
(a) The RAMBAM, ROSH in the name of RAV HAI GA'ON, PISKEI HA'ROSH of the TUR, and TALMIDEI RABEINU YONAH write that the Gemara means that a person should choose one opinion to follow, and he should act in accordance with that opinion consistently for his entire life. He should not switch between opinions and pray one day like the Rabanan and another day like Rebbi Yehudah. This ruling is based on the Gemara in Eruvin (7a) which says that a person should choose a Halachic authority to follow and he should not switch from one authority to another.
(b) RABEINU TAM (as cited by the ROSH 1:1), the ME'IRI, and the RE'AH understand that a person may pray Ma'ariv between Plag ha'Minchah and sunset on some days, and on other days pray Minchah during that same period. However, he may not recite both Minchah and Ma'ariv after Plag ha'Minchah and before sunset on the same day. They explain that while normally it is prohibited to act in accordance with two varying opinions, Tefilah is an exception because it is only mid'Rabanan. Therefore, the Rabanan permitted one to choose to follow different (and contradicting) opinions on different days.
(c) RABEINU TAM cited by TOSFOS (2a, DH Me'eimasai) maintains that even on the same day one may recite Minchah after Plag ha'Minchah and Ma'ariv before sunset. The Me'iri also quotes some authorities who rule this way and explain that the time period between Plag and sunset "serves both day and night" ("Meshamesh Yom v'Lailah"). According to these opinions, the Rabanan were lenient with regard to Tefilah even to the extent that they permitted one to follow two opposing opinions.
HALACHAH: The SHULCHAN ARUCH (OC 233:1) rules like the Rambam and the Rosh, who say that a person should choose one opinion and follow it for the rest of his life. In case of necessity, however, one is permitted to switch and follow the other opinion on a different day, as the Re'ah says.
The DERECH HA'CHAYIM says that some people are lenient and recite Minchah after Plag and Ma'ariv before sunset (like Tosfos) when doing otherwise would cause undue inconvenience to the Tzibur. The MISHNAH BERURAH (OC 267:3) writes that one should not rely on this opinion in practice.
With regard to Friday night, the Shulchan Aruch (OC 267:2) writes that the custom is to recite Ma'ariv earlier than on the weekdays (that is, earlier than usual, but not necessarily to recite Ma'ariv before sunset). The Magen Avraham adds that one may even recite Ma'ariv before sunset on Shabbos, even if he normally does not recite Ma'ariv before sunset. Apparently, the Rabanan were lenient and permitted one to follow a different opinion in order to fulfill the Mitzvah of Tosefes Shabbos (adding to Shabbos). The Mishnah Berurah (267:3) adds that when one recites Ma'ariv early on Friday night, he should be careful to recite Minchah before Plag ha'Minchah in order to avoid acting simultaneously in accordance with two contradicting opinions. (Thus, we see that in practice the third opinion is never followed.)
27b----------------------------------------27b
2) REBBI ELAZAR BEN AZARYAH ASKED HIS WIFE
QUESTION: Rebbi Elazar ben Azaryah refused to accept a leadership position until he asked his wife. Why did Rebbi Elazar ben Azaryah need to ask his wife? What were his doubts?
ANSWER: RAV YONASAN EIBSHITZ in YA'AROS DEVASH (cited in MAHARATZ CHAYOS) explains that the Gemara in Kesuvos (61b) states that a man who works as a donkey driver (whose conjugal obligation to his wife is once a week) who desires to become a camel driver (whose conjugal obligation is once every thirty days) must ask his wife for permission. His career-change will cause a decrease in the frequency of her conjugal rights (Onah), and she must give her permission first.
The Gemara there states that a Talmid Chacham's conjugal obligation is once a week, "from Shabbos to Shabbos." A Nasi's conjugal obligation is once a month (as is stated in Avos d'Rebbi Nasan). The choice to become a Nasi would affect his wife, and therefore Rebbi Elazar ben Azaryah needed to ask her for permission!