What is the ruling on a Muslim slaughtering a sheep belonging to a Majusi (Zoroastrian) or an infidel, designated for their fire temple or their deities, in the Islamic manner, while invoking the name of Allah? Is this considered polytheism (shirk) or a sin, and what is the ruling on the slaughtered sheep? Is there any text that permits this in the manuscript "Jami' al-Fatawa"?

It is not permissible for a Muslim to slaughter what he knows is an offering to other than Allah, because it involves condoning evil and cooperating in sin. It also falls under what has been consecrated to other than Allah and what has been slaughtered on altars. These sacrifices are considered carrion, and it is not permissible to eat from them even if the name of Allah was pronounced over them. The Muslim who slaughters them is not considered a polytheist unless he intended to glorify the one for whom the sacrifice was made. Slaughtering for other than Allah or for the glorification of a person makes its meat unlawful to eat, even if the name of Allah was pronounced over it.