[If] one prepares an idolater’s wine in purity, and he places it in his domain in a house which opens onto a public domain —- [if it is] in a city which has idolaters and Jews in it, it is permitted; [but] in a city which is entirely idol worshipers, it is forbid-den, unless he appoints a watchman. The watch- man need not be constantly present and guarding —- even if he leaves and returns, it is permitted. R’ Shimon ben Elazar says: All idolatrous domains are one.