2,404. A Common Courtyard

Maachalos Assuros 12:20

Let’s say that a non-Jew and a Jew share a common courtyard and they both left suddenly to see a wedding procession or a funeral procession. If the non-Jew returns first and closes the courtyard entrance before the Jew returns, open vessels of wine in the Jew's home remain permitted. We are not concerned that the non-Jew might have gone into the Jew’s home because, as far as he knew, the Jew might have come home first.

Maachalos Assuros 12:21

Let’s say that wine belonging to a Jew and to a non-Jew was in the same building and the barrels were open. If the non-Jew entered and locked the door behind him, all the wine is rendered prohibited. If there’s a window in the door through which a person on the other side can see directly in front of him, all of the barrels opposite the window remain permitted while those that are off to the sides are prohibited. This is because the non-Jew is concerned about those who can see him.