Is every pure thing permissible to eat, and is every repulsive thing forbidden to eat on the grounds that it is among the abominations? What is the criterion for a forbidden repulsive thing, and is a small amount of it excused?

The fundamental principle concerning pure things is the permissibility of benefiting from them. The use of a pure substance is not forbidden unless it is harmful or intoxicating. As for pure but repulsive things, eating them is reprehensibly disliked (makruh tanzihi), and the criterion for what is considered repulsive reverts to common custom. Regarding the evil/vile (khabith) and forbidden, scholars have differed. Some believe it refers to what the Arabs of Hijaz considered evil during the time of the Prophet, peace and blessings be upon him. In contrast, the Malikis and those who agree with them hold that it is anything harmful to bodies or minds. This latter view is the most correct, for everything Allah has made lawful is good (tayyib), and everything He has forbidden is evil/vile (khabith). What is forbidden among the evil/vile things is equally prohibited whether in small or large quantities, except in cases of necessity.