What is Be'er Miryam?

Rashi: It is the well that accompanied Bnei Yisrael in the Midbar, in her merit.

Etz Yosef: After she died, there was no water for Yisrael. Many ask, since it returned in the merit of Moshe and Aharon (Seder Olam Rabah 10), why did it depart initially? This was to show that it was in her merit. Similarly ,when Aharon died, Anenei ha'Kavod departed, to show that they were in his merit. Since Moshe's merit alone returned them, why were they not given from the beginning in his merit? SHLaH answered that returning something that already was, requires less merit than to be Mechadesh something that was not yet in the world.

What is the significance of seeing her well?

Daf Al ha'Daf: Vayikra Rabah (22:2) says that a leper bathed in it, and he was cured. Bamidbar Rabah (18:22) says that a blind person immersed in it, and his eyes were cured. The Ari Zal gave from its water to R. Chaim Vital to drink, to enable him to understand secrets of Torah (also Rav Elyashiv brings this). Perhaps anyone who sees it, this helps to understand spiritual matters. Some (cited in Rema OC 299:10) say to draw water every Motza'ei Shabbos, for Miryam's well goes around all the wells, and one who drinks from it will be cured from all his illnesses. Rema did not know the source. Kol Bo (41) says that once, a leper's wife went to draw water for him on Erev Shabbos. The flask broke, and wherever the water came on him was healed. This is the source!

Where is her well?

Rav Elyashiv: The Midrash says that it is in the Kineres. The Gemara discussed descending from the top of Karmel to immerse in it. If so, this is not what we call Karmel, which is by the Yam ha'Gadol. Rather, it is in the east of Eretz Yisrael.

Daf Al ha'Daf: Rashi (Bamidbar 21:20) says that it was hidden in Yam Tiverya; one who stands on ha'Yeshimon sees like a sifter in the sea. The Yerushalmi (Kil'ayim 9:3) says so. Our Gemara says that one sees it from Har ha'Karmel! Pnei Moshe says that Har ha'Karmel is ha'Yeshimon. Also Chasam Sofer (Haftoras Ki Sisa) says that Karmel is near Yam Tiverya. Radal (on Vayikra Rabah 22:4) questioned this, for Har ha'Karmel is in the west, by Yam ha'Gadol! Perhaps Pnei Moshe and Chasam Sofer rely on R. Chananel. His text here says 'he descends from Karmel and immerses in Yam Tiverya.'

What will he see like a sifter?

Rashi: He will see a round rock shaped like a sifter.

In what sense is it Tahor?

Rashi: It is not Mekabel Tum'ah, and one may immerse in it, for it is not considered a Kli, so its water is not considered She'uvim.

Rav Elyashiv: In any case, stone Kelim are not Mekabel Tum'ah! Seemingly, Tahor means that one may immerse in it!

Daf Al ha'Daf citing Pardes Yosef (Metzora 52) citing the Imrei Emes: What is the Chidush that one may immerse in it? Mayim She'uvim is Pasul because man's strength was involved. One might have thought that the same applies to Miryam's well, about which it says "Ali Ve'er Enu Lah" - it was due to Yisrael's Tefilah. (NOTE: In the Midbar, each Nasi dug a furrow, and water came to his Shevet, and people immersed in it, even though man's physical strength was involved! If a Mikveh that is totally She'uvim is Kosher mid'Oraisa, the Chidush is, even after Chachamim decreed, it is Kosher. - PF)

What is the Chidush of one who did Melachah during two Bein ha'Shemashos?

Rashi: It was Bein ha'Shemashos of Erev Shabbos and of Motzei Shabbos, in one Helam (he did not remember in between that this is forbidden). He is not Chayav Asham Taluy (for one who has a Safek if he transgressed), rather, he is Chayav Chatas.

R. Akiva Eiger, Daf Al ha'Daf citing Parnes ha'Dor: Why did Rashi say that it was in one Helam? Also if it was in two Helamos, he is Chayav Chatas! If there were two Helamos, he would be liable also Asham Taluy, for if part of Bein ha'Shemashos is day and part is night, he is liable two. Since it is a Safek if he is liable a second Chatas, he brings Asham Taluy in place of it. Parnes ha'Dor - a Chacham asked, R. Gamliel says that if one wrote one letter in the morning and one in the evening, he is liable twice (105a). Rashi explained, since he had enough time to remember, it is like two Ha'alamos. Also, here is like two Helamos! I answered, here we discuss forgetting the Melachah. There, he forgot Shabbos; he had enough time to remember in between that it is Shabbos.

Rav Elyashiv: Yedi'os obligate Chata'os. If one ate 10 k'Zeisim of Chelev, and found out about one at a time, each Yedi'ah obligates another Korban. Here, uf there were two Helamos, when he found out in between, it was only Safek, so it did not obligate a Korban. Also when he later learned of the second Helam, it is a Safek Yedi'ah, so 'mi'Mah Nafshach' would not obligate a Chatas!

Why does it say 'mi'Mah Nafshach'?

Rashi: If Bein ha'Shemashos is night, he did Melachah when Shabbos began! If it is day, he did Melachah on Shabbos! The case is, he did Melachah all of Bein ha'Shemashos, so there is no concern lest [part of Bein ha'Shemashos is day, and part is night, and he is exempt, for] he began the Melachah during the day and finished at night.

Daf Al ha'Daf: Megilas Sefer (212) says that Bein ha'Shemashos is a Safek only to Chachamim. It is not considered a Safek to Shamayim (clearly, even if it were considered a Safek, it is not due to a lack of knowledge above!), for we bring a Korban due to mi'Mah Nafshach. However, the Vilna Gaon says that it is considered a Safek to Shamayim. There is no Safek at the beginning of daytime. All agree that dawn begins daytime. Why is night different? Rather, a tradition from Sinai teaches that the end of the day is considered Safek. Rashi (Bereishis 2:2) says that only Hash-m knows the exact time when the day ends. The Vilna Gaon brought this Midrash in Avos (5:6), regarding the 10 matters created Bein ha'Shemashos.

Rav Elyashiv: The Ritva Yoma (47a) says that Bein ha'Shemashos is neither day nor night. Here it says that it is either day or night, therefore he is liable! Here Rashi said that right after Bein ha'Shemashos [of R. Yehudah on Motza'ei Shabbos], Melachah is permitted. It is forbidden due to Tosefes Shabbos! (NOTE: Rashi said only 'Eino Klum', there is no liability for Motza'ei Shabbos. He did not permit l'Chatchilah! - PF) Perhaps he holds like the Rambam, that there is no Tosefes Shabbos. The Chiyuv of Tosefes Shabbos at the end of Shabbos is greater than at the start (Mordechai Shabbos 798).

Daf Al ha'Daf: Reishis Bikurim (Bechoros 42b) answered for the Ritva. The Isur of Erev Shabbos is weaker because Bein ha'Shemashos is partially day. The Isur of Motza'ei Shabbos completes the Chiyuv, for its day component is liable. He supported himself from the Ramban (Tum'as Mishkav 1) who says that if an Androginus (one who has male and female genitals) had an emission of blood or semen, he is Safek Tamei. If he had both, he is Vadai Tamei. Lechem Mishneh (Hilchos Ishus 4) asked, he ruled that Androginus is a new creation; he is not a Safek male, Safek female! I answer that because male and female are mixed in him, this weakens the Isur and there is no punishment. If an Arus annulled his Arusah's vow, or her father annulled it, this weakens the Isur, and there are no lashes for the vow (Nedarim 68a). If he had both emissions, he is Vadai Tamei, for he is Tamei from both sides.

Why did Rava tell him to light Ner Shabbos when the sun is seen at the top of date trees?

Rashi: It is Vadai day.

Why should one look at roosters or ravens?

Rashi: When they sit on beams [it is still day].

Rav Elyashiv: Hens lay eggs only during the day (Beitzah 7a). If one sees it lay an egg, it is day. (NOTE: Our text say 'Tarnegola', i.e. a male! Also, the Gemara tells how to know when day ends on a cloudy day. What is the chance that a hen will lay an egg at that time?! - PF)

What is Adani?

Rashi: It is mallow (a flower). Its leaves lean towards the sun. In the evening, they are totally bent to the west.

Etz Yosef: The Aruch's text is Harni. It is an herb with a round leaf. During the day, the leaf's opening faces the sun. At sunset, [the leaf] bends to the ground.