Pork — the flesh of swine — is forbidden by clear text in four places of the Qur'an and by the consensus of the Muslims. The prohibition includes the meat, the fat, and any product derived from it such as gelatine and rennet sourced from pigs. A Muslim does not need to know the wisdom behind a prohibition in order to obey it; rather, hearing and obeying is the basis of submission to Allah. Even so, scholars and modern science have noted that the pig is a scavenger that consumes filth and that its flesh carries unique health risks. The only exception is the case of necessity — a person whose life depends on it with no other food available, who may eat the minimum to survive without exceeding need.