The Beraisa permits doing business with both a Nochri and a Yisrael who are going to the market (where they deal with Avodah-Zarah and other commodities. Upon their return however, the Tana permits selling to a Nochri but forbids selling to a Yisrael.

The reason that he is strict regarding a Yisrael is - because we suspect that he went to the market in order to sell an Avodah-Zarah, and that the money that he has with him is D'mei Avodah-Zarah ...

A Nochri on the other hand, may well have gone to the market in order to sell clothes or a donkey and the like.

We do not say the same by a Yisrael - because if he had wanted to sell such things, he would have sold it in his home-town and not gone to a market of Avodah-Zarah (see Tosfos in the first Perek, 12: DH 'Aval').

The Beraisa permits new skin flasks of Nochrim that have not been overlaid with pitch - because they have not yet had a chance to absorb the wine that they contain.

If the jars are made of earthenware however - they are forbidden, since earthenware begins to absorb immediately.

The Tana - forbids old flasks or new ones that have been overlaid with pitch, because either way, the flask will then absorb the wine.

Now the Tana discusses a case where a Nochri overlays leather flasks with pitch and immediately pours in the wine - because they then imbibe some of the sharp taste of the pitch, thereby improving in quality.

He permits the wine - provided a Yisrael oversees the process.

We object to this leniency however - in that, seeing as it is the Nochri who pours in the wine, what difference will it make if a Yisrael oversees the process?

Rav Papa therefore amends the Beraisa to read that - it is the Yisrael who pours in the wine after the Nochri has poured the pitch.

One nevertheless needs a second Yisrael to oversee the procedure - because otherwise we are afraid that the Nochri will take advantage of the fact that the Yisrael is busy pouring the wine, and render the wine Yayin Nesech.

Rav Z'vid re-establishes the Beraisa as it was presented, and the reason that the Tana permits the wine on the basis of the Yisrael who is overseeing is - because the wine that becomes absorbed in the cask, goes completely to waste (like pouring water into mud [see Ritva]).

Rav Papi extrapolates from Rav Z'vid's ruling that - if a Nochri pours wine into a vessel containing salt, the salt is permitted (because there too, the wine has gone completely to waste).

Rav Ashi refutes Rav Papi's proof however - because (unlike the case of the pitch, where the wine disappears and dries up) the wine in the salt remains intact, seeing as a. it never dries up, and b. it gives taste to the salt.

bar Adi was a Nochri ...

... who forced Rebbi Yitzchak bar Yosef to give him his leather flasks, which he filled with wine, and later returned.

When Rebbi Yitzchak bar Yosef came to the Beis-ha'Midrash to ask what to do, Rebbi Yirmiyah quoting Rebbi Ami ruled that - for the flasks to be permitted, he would have to fill them with water for three consecutive days, and pour the water out (a process known as 'Shtelling').

Rava added - that he had to change the water after each twenty-four hour period.

When Ravin arrived from Eretz Yisrael, he quoted Resh Lakish - who extended this ruling even to a case where the flask belonged to the Nochri to begin with (even though it would have absorbed far more wine).

Rav Acha b'rei de'Rava thought that perhaps the lenient ruling is restricted to skin flasks, but does not apply to earthenware casks - which tend to absorb a lot of wine on the one hand, and which do not exude all that they absorb, on the other.

Rav Ashi told him that - earthenware casks in this regard, have the same Din as skin flasks.

The basic Halachah of 'Shtelling' earthenware wine-jars of Nochrim in water is taught in a Beraisa. The Tana dispenses with the need for Shtelling, permitting the jars to be used immediately - if one uses them for fish-juice or fish-hash (whose sharpness quickly dispel any wine that the jars have absorbed.

In answer to our query as to whether this leniency applies even Lechatchilah, or only Bedi'eved (permitting the fish juice ... that he already poured into the cask), Rav Z'vid bar Oshaya answers with a Beraisa - which specifically permits it even Lechatchilah.

When Rebbi Yehudah Nesi'ah asked Rebbi Ami whether returning the wine-casks to the furnace would suffice to permit them, he replied - that if fish-juice burns up the wine, how much more so, the heat of a furnace.

According to one version, Rebbi Ami concurs with this ruling. According to a second version, it is Rebbi Asi quoting - Rebbi Yochanan who concurs with it.

In fact, he permits the jars as soon as the pitch falls off from the heat. Rav Ashi commented that - what Rebbi Yochanan meant was that it is sufficient for the pitch to come loose.

We ask what the Din will be if one heats the jars by placing boiling hot rods inside them, until the pitch falls off, which might not be as good as returning them to the furnace - because seeing as the pitch is inside the jars together with the rods, it will require a lesser temperature to remove it than that of a furnace, where the heat has to loosen the pitch from the outside of the jars.

Rav Acha and Ravina argue over the previous She'eilah. The Halachah is - that it is Asur.

We learn from here that - one cannot Kasher barrels or jars that were used for storing wine, by pouring boiling water into them (since hot water is certainly no better than fire).

Rav Nachman and Rav Yehudah forbid using the barrels even for beer, unless they have been Kashered. Nevertheless, Ravina permitted Rav Chiya b'rei de'Rav Yitzchak to use them for beer, like the opinion of Rava. The latter subsequently (erred and) - used them for storing wine.

Why did Ravina not decree against using the jars for beer - because, he claimed, that was a chance error that was not likely to recur.

When Rav Yitzchak bar Bisna filled jars made of earthenware and animal dung that had been used with Yayin Nesech, and placed them in the sun - in order to Kasher them ...

... they broke.

Rebbi Aba commented - that Rav Yitzchak had lost his jars quite unnecessarily, since it was not necessary to place in the sun.

Rebbi Yossi bar Avin translated 'K'lei Neser' as receptacles made of alum. Rebbi Yusna ruled that - they cannot be Kashered.

The men of Parzak Rufila - Parzak the viceroy, took by force from Pumbedisa, used them once for wine and later returned them.

Rav Yehudah ruled that - since the wine was not stored in the casks, they only needed to be rinsed with cold water.

Rav Avira - issued the identical ruling with regard to barrels of red clay that one obtains from Nochrim, (even assuming that they have been used for storage) ...

... as did Rav Papi regarding 'Pasvasa de'bei Michsi' - earthenware vessels that come from an area where the clay is hard.

The common reason for the two previous rulings is - because neither of them absorb much wine.

Rav Asi requires earthenware cups to be Kashered, Rav Ashi does not. They argue in a case where a Yisrael drank from the cup for the first time, and it is from the second time and onwards that the Nochri drank from it; but if he were to drink from it the first time, then even Rav Ashi would concede that it requires Kashering - because since the cup is soft it initially absorbs easily.

The second Lashon, which is Halachah, takes a more stringent line - requiring Kashering even after the second time according to both opinions, and it is only after the third time that they argue.

The second Lashon is Halachah.

Rav Z'vid permits a black or white earthenware vessel covered with lead (see also Tosfos DH 'Kunya') - but not a green one, because it consists of Alum, which absorbs more (as we learned earlier).

He will require even a black or white one to be Kashered however - in the event that they have cracks.

Mereimar, who is more lenient than Rav Z'vid - permits even green lead-covered earthenware vessels.

They asked him about having to Kasher these same vessels with regard to Pesach. The She'eilah does not pertain - to green vessels (even if they are smooth) because the alum that they contain, absorbs a lot and is therefore never subject to Kashering, as we learned earlier.

He replied that - he had seen them exuding, in which case they need to be Kashered.

And to reconcile his stringent ruling by Chametz with his lenient ruling by Yayin Nesech - he will establish the former by vessels that are used with hot, and the latter, by vessels that are used with cold.

He did not answer that, whereas Chametz on Pesach is d'Oraysa, S'tam Yeinam is only de'Rabbanan - because of the principle 'Kol de'Tikun, Ke'ein d'Oraysa Tikun' (the specification of the Rabbanan's Takanos are similar to the Torah law). Consequently, since the Chachamim forbade Yayin Nesech, they would have also given it the same specifications as if it was d'Oraysa.