(Mishnah): If a Jew left an idolater with his wine in his store, even if he is only coming and going, the wine is permitted. But if the Jew informed him of his plans, (the wine is prohibited if there is enough time) in order to pierce it, plug it up with plaster and let it dry.

(R. Shimon ben Gamliel): It is only prohibited if there is enough time to open its lid, seal it up and let it dry.

(Gemara): (The Mishnah's permission to drink the wine when the Jew was coming and going, is even) like R. Meir, who (was the stringent opinion in Maseches Taharos and) said that (if a learned person's wife left an Am Ha'Aretz's (ignoramus) wife alone in the house grinding wheat, if the grinding stopped, the house is tamei, as there is a concern that she touched taharos in the house. And if there were two such women grinding) even if the grinding continued, the house is tamei.

(R. Chama citing R. Yosi bar Chaninah): If there was a courtyard divided with a low partition between a learned person and an Am Ha'aretz and the learned person had left items near the partition; if he had left taharos, they are considered tamei (as we are concerned that the Am Ha'Aretz reached over and touched them); but he had left wine, we do not consider it to be Yayin Nesech.

Question: Was R. Chama speaking only according to R. Meir who was stringent in Taharos and lenient in Yayin Nesech; or even according to Rabbanan?

Answer: He is speaking according to all opinions, as even Rabbanan are stringent in Taharos and lenient in Yayin Nesech.

(Mishnah): If a Jew was eating with an idolater at the table and he placed an open container on the table and another container on the side table and then he left them and went out, that which is on the table is prohibited and that which is on the sideboard is permitted.

If he told the idolater that he can pour and drink as he wishes, even the wine on the sideboard is prohibited.

Open barrels are prohibited; sealed barrels are prohibited if there is enough time for him to pierce it, plug it up with plaster and let it dry.

They wanted to suggest that whatever is on the table is prohibited if it within hand's reach; whatever is on the sideboard is permitted even if it is within hand's reach (since guests do not usually take wine from the sideboard).

Question: Didn't R. Ba cite Rav Sheshes as saying that just as the Chachamim were stringent about reaching for matters of Taharah, so they were stringent about reaching for Yayin Nesech. (So why is the wine on the sideboard permitted even if it is within hand's reach?)

Answer: Rather, whatever is on the table, even beyond hand's reach, is prohibited and whatever is on the sideboard is permitted, as long as it is beyond hand's reach.