1) READING BY THE LIGHT OF A FLAME
QUESTION: The Gemara (end of 12b) says that although one may read the "Roshei Parshiyos" (chapter headings) by the light of a flame on Shabbos (because one knows them by heart and does not need to look intently into the books, -Rashi), he may not read the entire chapter (because this requires more concentration and we are concerned that he may inadvertently tilt the lamp). The Gemara challenges this ruling from a Beraisa which states that the schoolchildren would study the Torah portion by the light of a flame.
Why does the Gemara ask from a Beraisa, when the Mishnah (11a) also states that children study by the light of a flame? (This question is valid only according to Rashi's first explanation of the Mishnah.)
(a) TOSFOS (DH Meisivei) answers that the Gemara does not ask from the Mishnah, because it is possible that the Mishnah is referring to children who wrongly read by the light of a flame. The Gemara could not ask from the Mishnah that reading by the light of a flame is permitted, because the children mentioned in our Mishnah are doing so improperly.
(b) The RASHBA explains that the Mishnah refers to when the children are reading in front of their Rebbi. Since the fear of their Rebbi is upon them, they will not make any movement, and certainly they will not tilt the lamp, without their Rebbi's express permission. The Beraisa, in contrast, is discussing children who are reading when their Rebbi is not present, and therefore the Gemara asks that we see from the Beraisa that it is permitted to read by the light of a flame. The Gemara answers that even though their Rebbi is not present, they still sit in fear of him and therefore there is no concern that they will tilt the lamp.
(c) The RITVA and VILNA GA'ON answer that the Mishnah refers to when the Rebbi is reading with his students, and therefore they are like two people reading together. The Gemara earlier says that two people may read together by the light of a flame because they will guard each other from tilting the lamp. In the case of the Beraisa, though, the Rebbi is not reading with the students.
(d) RAV NISIM GA'ON quotes the Yerushalmi that gives another answer for the Gemara's question from the Beraisa. The Yerushalmi answers that the case in the Beraisa is different; children are permitted to study by the light of a flame because we have no fear that they will tilt the lamp, because they want the flame to go out (and tilting the lamp lengthens the time that it burns) so that they can stop learning and go play!
Perhaps the Gemara understands that the Mishnah refers to such children who would never even attempt, even accidentally, to lengthen the time that they have to sit and study, which is why they are permitted to read by the light of a flame. However, the Beraisa is discussing children who are "preparing their studies for the following day," in which case there is a concern that they will tilt the lamp in order to make sure that they do not run out of time to finish what they need to study. (M. KORNFELD)
2) HALACHAH: EATING WITH ONE'S WIFE WHO IS A NIDAH
QUESTION: In the account (cited from Tana d'Vei Eliyahu) of the young scholar who died as a result of his improper conduct with his wife when she was a Nidah, the wife of that scholar said that during the days of Libun he ate and drank with her and slept in the same bed with her. Eliyahu exclaimed that the young scholar deserved to die, because the Torah prohibits such close contact between a man and his wife when she is a Nidah.
Is eating and drinking with one's wife when she is a Nidah prohibited? If it is not prohibited, then why does the Gemara record that they ate and drank together?
(a) TOSFOS (DH bi'Yemei Libunech) says that the Gemara records that they ate together for no special reason, but rather simply because that is what happened. Eliyahu's exclamation was only in response to the fact that they slept in the same bed together. There is nothing wrong with eating and drinking with one's wife when she is a Nidah.
(b) The ROSH (1:32) says that their eating and drinking together was indeed inappropriate, because in those days they used to eat on a single, small table, and eating together on such a small table was considered an activity of intimacy. The Rosh adds that even today, when we eat at large tables, it is best for a man and his wife who is a Nidah to place an object as a reminder between them while they eat. (The HAGAHOS ASHIRI writes that if they usually eat from one plate, then they should eat from two plates, and no further reminder is necessary. Perhaps the young scholar and his wife ate from one plate, which was improper.)
HALACHAH: The SHULCHAN ARUCH (YD 195:3) rules like the Rosh (and many other Rishonim) that one may not eat at the same table with one's wife who is a Nidah unless they place an object (which is not normally placed on the table) between them, or their plates are placed on separate tablemats. The REMA cites and rules like the Hagahos Ashiri that if a husband and wife normally eat together from one plate, then when she is a Nidah they may eat from two separate plates without any additional reminder.
The SHACH cites the BACH who adds that besides eating from separate plates, they must also have other members of the household sitting at their table.