1) HALACHAH: A BLESSING FOR A "SAFEK MITZVAH"
OPINIONS: The Gemara teaches that we must recite a blessing on all Mitzvos d'Rabanan. Rav Amram questions this assertion from the Mishnah in Demai (1:4) which says that one may separate Terumah from Demai (doubtfully tithed produce) even while one is unclothed. If we must recite a blessing on all Mitzvos mid'Rabanan, then why may one separate Demai when unclothed? One may not recite a blessing while unclothed!
Abaye answers that we must recite a blessing only on all Vadai Mitzvos d'Rabanan, but not on Safek Mitzvos d'Rabanan, such as Demai.
Rava answers that we do not recite a blessing for the Mitzvah of separating Terumah from Demai because Demai is not even considered a Safek, as most Amei ha'Aretz are careful to tithe. As RASHI (DH Rava Amar) explains, the requirement to separate Terumah from Demai is not due to a doubt, but rather it is a "Chumra b'Alma," a stringency established by the Rabanan.
Rava's words imply that he argues with Abaye and maintains that in all other cases of a Safek Mitzvah d'Rabanan (for example, when one is in doubt whether or not he fulfilled his obligation to perform a Mitzvah d'Rabanan), he must recite another blessing when he performs the Mitzvah again.
Is this indeed the Halachah?
(a) The RAN writes that Rava requires that one recite the blessing again in a case of a doubt only when the doubt involves whether or not he performed a Mitzvah d'Oraisa. Since he must perform the Mitzvah again out of doubt, he must also recite the blessing again. However, when the Mitzvah itself is the blessing (for example, one is unsure whether he recited "Emes v'Yatziv"), one does not recite the blessing again out of doubt, as the Gemara in Berachos (21a) says.
This also seems to be the intention of RASHI (DH Rava Amar). The RA'AVAD rules like this (Hilchos Milah 3:6), as does RABEINU YONAH (Berachos 21a). However, this ruling applies only when one is in doubt whether he did the Mitzvah or not. If one knows that he did the Mitzvah but is in doubt whether he recited the blessing, he does not recite the blessing again.
(b) The RAMBAM (Hilchos Milah 3:6, Hilchos Tzitzis 3:9), however, writes that one does not recite a new blessing when one performs a Mitzvah when he has a doubt whether he did the Mitzvah or not. This is also the view of the RIF and RAV HAI GA'ON as quoted by the Ran. The Poskim rule in accordance with the opinion of the Rambam.
According to this opinion, what does Rava mean when he says that the reason why we do not recite a blessing when separating Terumah from Demai is because Demai is not a real Safek? This clearly implies that in the case of a real Safek Mitzvah d'Rabanan, one does recite a blessing!
The RAMBAN (as cited by the Ran) explains that we might have thought that since the Rabanan established the requirement to separate Terumah from Demai, that requirement has the status of a Vadai Mitzvah d'Rabanan, for which we must recite a Berachah. Rava therefore explains that since most Amei ha'Aretz separate Terumah, when one separates Terumah from Demai he is doing so only out of doubt, and therefore he does not recite a blessing, just as one does not recite a blessing for any Safek Mitzvah d'Rabanan.
3) HALACHAH: THE CHANUKAH LIGHTS TAKE PRECEDENCE
QUESTION: The Gemara says that buying Chanukah lights takes precedence over buying wine for Kidush, because the Chanukah lights involve Pirsum Nes, the publicizing of the miracle of Chanukah. The RAMBAM takes this further and rules that one should even sell his clothing in order to buy the materials needed for kindling the Chanukah lights. The Rambam writes, "The Mitzvah of the Chanukah lights is a most beloved Mitzvah, and one must be very prudent in its fulfillment in order to publicize the miracle and to increase the praise of Hash-m and gratitude to Him for the miracles that He wrought for us. [Therefore,] even if one [is so poor that he] has nothing to eat except for what he takes from charity, he should borrow money or sell his clothing in order to buy oil and candles to light" (Hilchos Chanukah 4:12).
What is the Rambam's source for this ruling?
(a) The MAGID MISHNEH explains that the Rambam's source is the Gemara here, which says that the publicizing of the Mitzvah of Chanukah makes the Chanukah lights more important than Kidush. We find with regard to the Four Cups of wine of the Seder night that if one cannot afford to buy wine, he should take charity in order to buy wine to fulfill the Mitzvah. The Gemara in Pesachim (112a) says that the Four Cups also serve to publicize a miracle. If one must take from charity in order to fulfill the Mitzvah of the Four Cups, then all the more so must one take from charity or sell one's clothing in order to fulfill the Mitzvah of the Chanukah lights.
(The LECHEM MISHNEH asks why the Magid Mishneh says "all the more so" regarding the Chanukah lights. Why should the Mitzvah of the Chanukah lights be more stringent than the Four Cups, if they are both Mitzvos d'Rabanan of Pirsum Nes? He concludes that the Rambam's ruling can be learned from comparing the two Mitzvos ("Hu ha'Din"), but not from the logic of "Kol she'Ken.")
(b) The VILNA GA'ON (BI'UR HA'GRA OC 671) says that the source for this Halachah is as follows. The Gemara in Pesachim (112a) says that even a poor person who is already supported by the communal charity fund should take more charity in order to provide a minimal amount of food in honor of Shabbos. The RASHBAM, in his comments to the Mishnah in Pesachim (99b), says that taking from charity means even hiring oneself out or selling one's clothing. The Gemara there (Pesachim 105b) says that one must rely on charity if he does not have enough money to buy wine for Kidush. Since the Gemara here says that the Chanukah lights take precedence over Kidush, we may derive that certainly one must sell his clothing to buy Chanukah lights.
(c) The ROGATCHOVER GA'ON in TZAFNAS PANE'ACH says that it is not necessary to prove from the Gemara in Pesachim that one is required to sell his clothing in order to buy wine for Kidush, because the Gemara elsewhere says so explicitly. The Gemara in Megilah (27b) relates that some of the Amora'im sold their clothing in order to buy wine for Kidush. Since the Gemara here says that the Chanukah lights take precedence over Kidush, we may derive that certainly one must sell his clothing to buy Chanukah lights.
4) WHEN TO LIGHT THE SHABBOS CANDLES
QUESTION: The Gemara relates that the wife of Rav Yosef used to light the Shabbos candles late. Rav Yosef pointed out that it is "proper etiquette" (Rashi) to light while it is still day.
How could the wife of Rav Yosef light the Shabbos candles late? Did she not know the explicit Torah prohibition against lighting a fire on Shabbos? Furthermore, if she was desecrating the Shabbos, why did Rav Yosef reprimand her with a metaphor instructing proper etiquette, and not with the explicit verse in the Torah that commands us to observe the Shabbos?
ANSWER: The RAN explains that Rav Yosef's wife certainly lit the candles before sundown and was not desecrating the Shabbos. However, she thought that although there is a Mitzvah to add to the Shabbos from the weekday ("Tosefes Shabbos"), that Mitzvah does not apply to lighting the Shabbos candles, and the Shabbos candles may be lit after Tosefes Shabbos, before sundown. Her reasoning was that Tosefes Shabbos applies only to the prohibition of Melachah (that is, one should cease from performing Melachah some time before sundown), but not to a Melachah that involves a hallowed act of a Mitzvah (lighting the Shabbos candles). Rav Yosef therefore informed her that it is proper to observe Tosefes Shabbos with the lighting of the Shabbos candles as well.
The Gemara continues and relates that after Rav Yosef told her that she should light the candles earlier, she wanted to light them very early. A certain elder told her that she should not light the candles too early, but rather after she ceases doing the other Melachos she should light the candles in order for the lighting of the Shabbos candles to be the last Melachah that she does before Shabbos.