1,137. Working for the Sake of an Idol

167:5 A cross that people bow down to may not be used without being nullified. A cross that is worn as a necklace by religious adherents need not be nullified.

167:6 One may not do anything for the sake of idols, not even installing the windows in the house of idolatry. One may not sell texts that are unique to the service of a given idol, nor even Jewish texts that have been edited in order to validate other religions. One may not sell idolators anything they need for their service when they could not get it elsewhere. Some authorities prohibit it to be sold even when they can get it elsewhere; it's advisable to act stringently in this matter.