Avodah Zarah 1:4-5

Avodah Zara 1:4

If there is an idol with a holiday being celebrated in a particular city, it is permitted to engage in business with idolators outside of that city. If there was an idol outside the city, then it is permitted inside the city. As far as traveling to an idolatrous city on the day of their holiday, if a road leads only to that city, it is prohibited but if one could take the road to another destination, then it is permitted. The Sages said that if a city has an idol with a holiday being celebrated and there are both decorated and undecorated shops, as was the case in Beit Sheian, then the decorated shops are prohibited to shop in but the undecorated shops are permitted.

Avodah Zara 1:5

It is prohibited to sell the following things to idolators (since they are likely to be used in idolatrous service): the fruit of cedar trees, white figs on the stalk, frankincense and a white rooster. Rabbi Yehuda says that one may sell him a bunch of roosters that includes a white rooster (since the idolator is apparently not purchasing it for idolatrous use). If there is only one rooster (and it’s a white rooster), the seller may cut off a digit and sell it to the idolator since this will render it unfit for use in idolatry. As far as other merchandise, if the idolator does not specifically request them for idolatrous purposes, it is permitted to sell them to him but if he did so specify, then it is prohibited. Rabbi Meir says that it is also prohibited to sell idolators choice palm dates, sugar cane and high-quality herbs (as these are also likely to be used in idolatrous service).