Avodah Zarah 61B

בחצר אחרת ⁠— מותר, והוא שמפתח וחותם בידו.

If a Jew dwells only in another courtyard, the wine is also permitted, but this is only when the Jew has the key to the house or a seal on the jugs of wine in his possession, as this prevents the non-Jew from gaining access to the wine.

המטהר יינו של גוי ברשותו, וישראל דר באותה חצר ⁠— מותר, והוא שמפתח וחותם בידו. אמר ליה רבי יוחנן לתנא, תני: אף על פי שאין מפתח וחותם בידו ⁠— מותר.

In the case of a Jew who renders the wine of a non-Jew permitted, and the wine is in the non-Jew’s domain, if another Jew dwells in the same courtyard, the wine is permitted, but this is only when the Jew has the key to the house or a seal on the jugs of wine in his possession. R' Yoḥanan said to the tanna reciting the baraita: In this case you should teach that even if that Jew does not have in his possession the key to the house or a seal on the jugs of wine, the wine is permitted.

בחצר אחרת ⁠— אסור, אף על פי שמפתח וחותם בידו, דברי רבי מאיר.

The baraita continues: If the second Jew dwells only in another courtyard, the wine is prohibited, even when that Jew has the key to the house or a seal on the jugs of wine in his possession. This is the statement of R' Meir.

וחכמים אוסרין, עד שיהא שומר יושב ומשמר, או עד שיבא ממונה הבא לקיצין.

And the Rabbis deem the wine prohibited, unless a watchman is sitting and safeguarding the wine constantly, or unless an appointed person comes to safeguard the wine. This is referring to a watchman who comes at set times.

חכמים אהייא? אילימא אסיפא ⁠— תנא קמא נמי מיסר קא אסר! ואלא ארישא דסיפא, והא קאמר ליה רבי יוחנן לתנא: תני אף על פי שאין מפתח וחותם בידו!

The Talmud asks: To which case in the baraita are the Rabbis referring? If we say that they are referring to the last clause, this is difficult, as in that case the first tanna, R' Meir, also deems the wine prohibited. Rather, perhaps they are referring to the first clause of the last clause, with regard to a case where a Jew renders a non-Jew’s wine permitted and another Jew dwells in the same courtyard. But didn’t R' Yoḥanan say to the tanna reciting the baraita: You should teach that even if the Jew does not have in his possession the key to the house or a seal on the jugs of wine, the wine is permitted? It may be assumed that R' Yoḥanan does not disagree with the opinion of the Rabbis.