DOES TASTING POGEM?
Objection (Rav Ashi): You seek to learn that tasting is Pogem and that there is a Shi'ur for the cup of Berachah from one matter [that he does not Mavdil and save some wine for Birkas ha'Mazon] - you cannot!
In the Beraisa, tasting is Pogem because there is a Shi'ur for the cup of Berachah [and he has exactly a Revi'is - but if he had more than a Revi'is, perhaps tasting would not Pogem as long as he leaves a Revi'is]!
R. Yakov bar Idi was particular not to use [for Mitzvos said over a cup] a Pagum flask (i.e. from which someone tasted, if he could get one that is not Pagum);
Rav Idi bar Shisha was particular not to use a Pagum cup.
Mar bar Rav Ashi was particular not to use even a Pagum barrel.
THE DAYTIME KIDUSH
(Beraisa): "Zachor Es Yom ha'Shabbos Lekadsho" - one should Zocher (mention) Shabbos (i.e. say Kidush) over a cup (this is an Asmachta - Kidush over wine is mid'Rabanan).
Question: This teaches about the day - what is the source to require Kidush at night?
Answer: "Zachor Es Yom ha'Shabbos Lekadsho" - at night (this will be explained).
Objection #1: Why do we [first learn about the day and] ask about the source to Mekadesh at night? "Lekadsho" connotes sanctifying the arrival of Shabbos, at night!
Objection #2: The Tana asked about the source for the night - how does he learn from "Zachor Es Yom...?"
Answer: It means, "Zachor Es Yom ha'Shabbos Lekadsho" - when Shabbos begins, one should mention it over a cup;
Question: This teaches about the night - what is the source for daytime Kidush?
Answer: "Zachor Es Yom ha'Shabbos."
Question: What Berachah does one make during the day?
Answer (Rav Yehudah): He blesses [only] Borei Peri ha'Gafen.
Rav Ashi visited Mechuza; [during the day] they asked him to make 'Kedusha Rabah (the great Kidush)' (he did not know whether or not their custom was to say the entire Kidush of Shabbos night). He said 'Borei Peri ha'Gafen', drawing it out; he saw an elder bend down and drink [and realized that this is all they say] - he applied to himself "Ha'Chacham Einav b'Rosho" (a Chachamim plans in advance. 'Kedusha Rabah' means the universal Kidush - Borei Peri ha'Gafen is part of every Kidush; alternatively, this is a euphemism, for it is really the small Kidush. R. E. M. Horowitz - he suspected that they were unable to make Kidush at night and wanted to be Yotzei through him; he was embarrassed to ask 'what is 'Kedusha Rabah?')
THE LAST TIME FOR HAVDALAH
(Benei R. Chiya): If one did not make Havdalah on Motza'ei Shabbos, he makes Havdalah [at his first opportunity,] any time during the week.
Question: Until when is it permitted?
Answer (R. Zeira): He may do so until [but not including] Yom Revi'i (Tuesday night), similar to [conditional] divorce:
(R. Zeira): Regarding a Get [given on condition that something be done in a certain time], 'after Shabbos' refers to the first three days of the week; 'Kamei (preceding) Shabbos' refers to the three days before Shabbos.
(R. Yakov bar Idi): [One may Mavdil until Yom Revi'i, but] one may not bless on light after Motza'ei Shabbos.
KIDUSH OR HAVDALAH AFTER ONE ALREADY ATE
(Rav Berona [and Rav Ada bar Ahavah] citing Rav): One who washed his hands should not say Kidush (it is an interruption between washing and ha'Motzi - therefore, he should hear Kidush from someone else).
Rav Yitzchak bar Shmuel: Rav is still alive, and you already forgot his teachings!
Sometimes when I was in front of Rav, he preferred bread [over wine, i.e. he was hungry] and was Mekadesh on bread - other times he preferred wine and was Mekadesh on wine.
(Rav Huna): If one ate [after Shabbos started], he does not Mekadesh.
Question (Rav Chana bar Chanina): If one ate [after Shabbos ended], does he Mavdil?
Answer (Rav Huna): I say [in the name of Rav] that he does; Rav Asi says that he does not.
R. Yirmeyah bar Aba visited Rav Asi; he mistakenly ate [before Havdalah] - they gave him wine and he said Havdalah.
Rav Asi's wife (to Rav Asi): You hold that one should not do so!
Rav Asi: Don't protest - he holds like his Rebbi (Rav).
(Rav Yosef citing Shmuel): If one ate, he does not Mekadesh; if one ate [after Shabbos ended], he does not Mavdil;
(Rabah citing Shmuel): If one ate, he is Mekadesh; if one ate, he is Mavdil.