[If] a city has an idolatrous service in it, it is permitted [to transact business] outside [the city]. [If] there was an idolatrous service outside it, it is permitted [to transact business] inside [it].  What is [the law] regarding going there? When the road leads solely to that place, it is forbidden; but if one can travel on it to another place, it is permitted.  A city which has in it an idolatrous service, and there were shops in it that were decorated and those that were not decorated —- this was [once] an incident in Beis Shean, and the Sages said: The decorated ones are prohibited, and the undecorated ones are permitted.

These are the things it is forbidden to sell to idolaters: itztirobalin, and white figs on their stalks, and frankincense, and a white cock. R’ Yehudah says: It is permitted to sell him a white cock among other cocks. When it is by itself, he [may] clip its toe and sell it to him, for they do not sacrifice anything defective to an idol.  All other things: if [their purpose is] unspecified —- it is permitted [to sell them]; but if [their purpose is] specified —- it is forbidden [to sell them]. R’ Meir says: Even fine dates (lit. date palm), and chatzav, and niklivam, it is forbidden for one to sell to idolaters.