1)

(a)A man should say to his wife on Friday afternoon, shortly before dusk: 'Did you separate Ma'asros? Did you arrange an Eiruv( provided both of these are necessary), and - 'Kindle the Shabbos-lights!'

(b)He should not say this earlier, because then, his wife is likely to say to herself that, since she has plenty of time, she will see to them later, and his reminder will have been in vain.

(c)During the week, casual eating (Achilas Arai) does not need to be Ma'asered - but Shabbos has a Din of a fixed meal (Achilas Keva), so whatever one eats, needs to be Ma'asered.

(d)A man cannot see whether or not, his wife has Ma'asered the food for Shabbos, or whether she has made an Eiruv - therefore, he asks her whether she has done it or not. The Shabbos-lights, on the other hand, have obviously not yet been lit, otherwise he would have seen them burning - so he instructs her to kindle them.

2)

(a)'Safek Chasheichah etc., Ein Me'asrin es ha'Vaday'. Clearly - Isurim de'Rabbanan are also forbidden during the period of dusk, since the Tana includes Eiruvin (which is purely de'Rabbanan) among the things that are prohibited.

(b)The Tana nevertheless permits the Ma'asering of Demai during the dusk period - because Demai is not even a full de'Rabbanan, as we learnt earlier (on Daf 23a).

(c)'Eravtem' incorporates Eruvei Techumin and Eruvei Chatzeiros. (However, from the Gemara later - see 3c - it would appear, that the Reisha of the Mishnah is confined to Eruvei Techumin, which is how Rashi explains in Gitin. Refer also, to 3c)

3)

(a)We learn from the Pasuk in Iyov "ve'Yada'ta Ki Shalom Ahalecha, u'Fakadta Navecha ve'Lo Secheta" - that a man should tell his wife things that are relevant to Shalom Bayis: i.e. to Ma'aser, ro make an Eruv and to light Shabbos-lights, because, if one has not Ma'asered, the food will be forbidden, without an Eruv, one cannot carry in the courtyard, and without the Shabbos lights they will be unable to eat; all things that will interfere with Shalom Bayis.

(b)When saying the things mentioned in the Mishnah - one should say them gently, if they are to be effective (because women [like men] do not like being shouted at.

(c)As we have already explained, most things are forbidden to be done after dusk. Another exception to the rule (besides that of taking Ma'aser from Demai), is Eruvei Chatzeros, which unlike Eruvei Techumin, does not have an Asmachta (a support from a Pasuk) in the Torah. It is purely mi'de'Rabbanan. Consequently - when the Mishnah permits making an Eruv during dusk, it refers to Eruvei Chatzeros. The Reisha, which forbids it, is speaking about Eruvei Techumin.

4)

(a)If the Eruv of the person who placed his Eruv before dusk was eaten before nightfall, and that of the one who placed his Eruv after dusk, after nightfall - both Eruvin are effective.

(b)The problem with this Halachah is - how can both Eruvin possibly be effective? If dusk is considered day, then the latter Eruv should be effective, and the former one, not; whereas, if it is considered night, then it should be the other way round?

(c)The reason for this is - because, dusk is a Safek de'Rabbanan. So, applying the principle 'Safek de'Rabbanan le'Kula', we treat each case independently. Consequently, as far as the first person is concerned, we consider it as day, and with regard to the second, night. (According to Tosfos, DH 'Sh'neihem', this case is speaking about Eruvei Chatzeros, which we learnt above, is more lenient. But by Eruvei Techumin, we would not rule so leniently).(If the Eruv was placed during dusk and eaten during dusk, it would not be effective anyway, since we only consider dusk as belonging partly to the day and partly to the night - le'Chumra, but not le'Kula - see Rosh, end of Si'man 22.)

5)

(a)It is forbidden to wrap food on Shabbos, even with a cover that retains the heat but does not increase it - because we are afraid that, when he comes to wrap the pot, he will, upon discovering that it has cooled down, re-heat it before wrapping it, in order that it should still be hot when he comes to eat it on Shabbos morning. (From this explanation of Rashi, it is clear that the principle of 'Ein Bishul Achar Bishul' does not apply to liquids that have gone cold - See Rosh, Perek Kirah, Si'man 10 and 11).

(b)It is permitted during the dusk period however - because then, most pots are boiling hot. So Chazal did not prohibit wwrapping them at that stage.

(c)It is forbidden however, to wrap with something which increases the heat, even on Friday afternoon - because, since he clearly wants to heat the food, we are afraid that he may place the pot on the ashes, and then, at night-time, when he discovers that the coals are dying, he will stoke them.

(d)This prohibition applies even to a pot that is fully cooked - because, in spite of the fact that one is unlikely to stoke a pot that is fully cooked, Chazal decreed on pots that are fully cooked, because of pots that are not. (This Sugya will be discussed further in the following Perakim).

6)

(a)Dusk might belong to the day, it might belong to the night. We give the dusk period the stringencies of both. This means - that if dusk belongs to the day, then, on Motza'ei Shabbos, one must consider it all as part of the day, and it will be forbidden to perform any work before the end of dusk plus a few minutes (to allow for 'Tosfos Shabbos' - the obligation to add on to Shabbos). Whereas if we consider it to be part of the night, then we must consider dusk of Friday evening as Shabbos, which means that one must bring in Shabbos at least a few minutes before dusk (to allow for Tosfos Shabbos).

(b)If a man sees Zivus throughout one dusk period, we must assume that perhaps the entire dusk period belongs either to the day or to the night, in which case, he has seen only one day, and is no more than a Ba'al Keri (unless he sees again the following day); or whether the first half of the dusk belongs to the day and the second half to the night, in which case, he will be a Zav, though he does not bring a Korban (since he has not yet had three sightings).

(c)If he sees throughout two consecutive dusk periods, we are faced with three possibilities - either that the first dusk belongs to the first day, and the second dusk to the second night, in which case, he will not be a Zav at all (only a Ba'al Keri); or that both dusk periods belong either to their respective days or to their nights, in which case, he will be a Zav who saw twice (who is Tamei for seven days, but does not bring a Korban); or the first dusk period belonged half to the day and half to the night, and the second, to the night only, or if the second dusk period belongs to both day and night, and the first, to the day only (not to mention if, in the last two cases, both dusk periods belong to both the day and the night) - when he will be a full Zav (who brings a Korban at the termination of his Zivus).

7)

(a)Rebbi Yehudah says 'Eizehu Bein ha'Shemashos, mi'she'Tishka ha'Chamah, Kol Zeman she'Penei Mizrach Ma'adimin. Hichsif ha'Tachton, ve'Lo Hichsif ha'Elyon, Bein ha'Shemashos'. The discrepancy between the implication of the Reisha and the statement in the Seifa is - that having first said that from sunset as long as the Eastern horizon is still red, is considered dusk, from which we can infer that once it has become dark in the East, it is night, how can he then refer to when it has gone dark in the East, as 'dusk'.

(b)

1. Rabbah quoting Rav Yehudah quoting Shmuel explains that what Rebbi Yehudah is saying is - that from the time the sun sets and the Eastern horizon is red until it gets dark in the East, is all part of dusk. It is not two stages, and one can make no inferences from the first part of Rebbi Yehudah's words.

2. Rav Yosef quoting Rav Yehudah quoting Shmuel explains that Rebbi Yehudah is actually stating three stages: From sunset as long as the Eastern horizon is red - is day (not dusk, as we learnt at first); when the East becomes dark, dusk begins, and night falls when it becomes dark from the Eastern horizon until the middle of the sky (and with this Rabah also agrees).

(c)Measured in Milin, the practical difference between them is - From the time that the Eastern horizon reddens until it becomes dark only one twelfth of a Mil (about one and a half minutes) - the difference between three quarters and two thirds of a Mil. According to Rabah, it is part of Bein ha'Sh'mashos, whereas according to Rav Yosef, it is not.

(d)Three parts of a Mil cannot mean three halves of a Mil, because then, why did he not say 'one and a half Mil'? Nor can he have meant three thirds of a Mil, because then he should have said 'one Mil'? Consequently, he can only have meant three quarters of a Mil.