The Messenger of Allah ﷺ forbade eating the meat of animals that feed on filth and drinking their milk.
نهى رسول الله ﷺ عن أكل الجلالة وألبانها.
Abu Dawud (3785), Tirmidhi (1824), and Ibn Majah (3189) narrated it through multiple routes from Muhammad bin Ishaq, from Ibn Abu Najeeh, from Mujahid, from Ibn Umar, who related it. Hakim (2/34) also narrated it from this route and remained silent about it. Tirmidhi said, "Hasan gharib." I say, it is indeed so, except that Ibn Ishaq did not state explicitly that he heard it directly, but he was corroborated in this. Abu Dawud (3789) and Hakim (2/34–35), and from both of them Bayhaqi (9/333), narrated it through the route of Ahmad bin Abu Siraj, who said, Abdullah bin Jahm informed me, saying, Amr bin Abu Qays told us, from Ayub Sakhtiyani, from Nafi, from Ibn Umar, who said, "The Messenger of Allah ﷺ forbade riding jallalah camels or drinking their milk."Its chain is hasan because of Amr bin Abu Qays Razi and Abdullah bin Jahm Razi, both of whom make the hadith hasan. It has another route narrated by Tabarani in Al-Kabir (12/304) and Al-Awsat (622), through the route of Hisham bin Ammar, who said, Ismail bin Ayyash told us, from Umar bin Muhammad, from Salim, from Ibn Umar, that the Messenger of Allah ﷺ forbade jallalah animals, their milk, and riding on their backs. Tabarani said in Al-Awsat, "No one narrated this hadith from Umar except Ismail." I say, Ismail bin Ayyash is truthful in his narrations from the Syrians, but confused in his narrations from others, and this is one of those, for Umar bin Muhammad is Umar bin Zayd bin Abdullah bin Umar bin Khattab, a Madinan who settled in Asqalan. Nevertheless, its chain is not problematic when used as corroboration. It has yet another route, though what has been mentioned is the best of them. In sum, the hadith is sahih by the combination of its routes.As for the word "jallalah," jallalah refers to an animal that eats jillah and filth. Jillah means dung, and the word was borrowed and applied to filth in general. Ibn Hibban said, "Jallalah is an animal whose fodder is predominantly filth. If the predominant fodder consists of pure, wholesome things, it is not considered jallalah." Al-Ihsan (12/221).Khattabi said, "It refers to camels that eat jillah, which is filth. Eating their meat and drinking their milk was disliked as a matter of cleanliness and avoiding impurity, because when they are fed on it, the stench is found in their flesh. This applies when the predominant portion of their fodder consists of it. But if they graze on pasture and are fed grain, and only obtain a small amount of jillah, they are not considered jallalah. Rather, they are like chickens and similar animals, which may occasionally get hold of something impure while their predominant food and fodder comes from elsewhere, in which case eating them is not disliked."He said, "People differed regarding eating the meat of jallalah animals and drinking their milk. Abu Hanifa and his companions, Shafii, and Ahmad bin Hanbal disliked it, and they said it should not be eaten until the animal is confined for some days and fed fodder other than filth. Once its meat becomes wholesome, there is no harm in eating it. It has been narrated in a hadith that cattle should be fed for forty days before their meat is eaten, and Ibn Umar used to confine a chicken for three days before slaughtering it. Ishaq bin Rahawayh said there is no harm in eating its meat after washing it thoroughly. Hasan Basri saw no harm in eating the meat of jallalah animals, and Malik bin Anas said the same." This concludes Khattabi's statement.I say, despite this excellent discussion, eating jallalah animals may lead to disease due to the presence of germs in their flesh, and these diseases may even manifest as epidemics. This is part of the prophetic wisdom behind forbidding the eating of their meat and the drinking of their milk.