[Rulings of Remnants]
The remnant of a human,
– Meaning that which remains after his drinking it, even when in a state of janabah. Or that of a disbeliever whose mouth is clean.
that whose meat is consumed
– Including a horse according to the most correct opinion
– And purifying without being disliked to use
– The remnants
Of a dog, pig and predatory animal
– Such as a leopard and fox
– It is regarded as heavy filth
– The remnants
of a cat,
– Which is domesticated
– Which walks in filth, if it does not then there it is not disliked
– The remnants of a
– Such as a hawk, falcon, kite and crow. If one is sure that there is no filth on its beak its remnant is not disliked
– It is slightly (tanzihi) disliked to use whilst other pure water is available, however if other pure water is not available it is not disliked. Likewise its consumption by a poor person is not disliked.
– Which is domesticated
and mule (baghl) are doubtful.
– Meaning it is pure, but there is no certainty in its being purifying. If a person can not find any other purifying water they perform wudu with this and also perform tayammum out of precaution. It is correct to perform either of the two first.
And perspiration is like the remnant.
– Meaning the sweat of all animals takes the ruling of purity and impurity as that of the remnant. Therefore it follows that the sweat of a donkey if it comes into contact with water renders it doubtful
 Because its saliva is produced from its body which is impure, thereby extension its saliva will also be impure. Therefore when it drinks from water it saliva comes into contact with it and renders it impure. See Maraqi al-Falah (p.19).
As for Imam Malik, he holds the view that their remnants are not impure, because he holds the view that all living creatures are pure. Imam al-Shafi agrees with Imam Malik regarding the purity of predatory animals due to that which is reported by Ibn Majah from Abu Hurayrah that he said: ‘The Messenger of Allah (Allah bless Him and give Him peace) was asked regarding the watering pools between Makka and Madinah, it was said to Him that dogs and predatory animals drink from them. He said: It has what it has drunk, and what remains is for us to drink and is pure.’ They also cite as evidence the narration: ‘Can we perform wudu from that which donkeys have leftover (from drinking)? He said: Yes, and also that which has been leftover from all predatory animals’. Reported by al-Darqutni in his Sunan (1/62)
The hanafis evidence for the impurity of that which predatory animals have drunk from is that which is reported from Umar and Amr bin al-Aas that they came to a pool of water, Amr bin al-Aas said: ‘O owner of the pool, do predatory animals drink from your water? Umar said: O owner of the pool do not tell us’. It is reported by Malik in al-Muwatta (1/23). The proof in this narration is that if the owner of the pool of water had informed them of predatory animals drinking from it, the companions would not have been able to us the water due to the prohibition of doing so.
The evidences for the two hadith cited as proof for the other madhabs is that the they relate to the earlier period of Islam before the meat of predatory animals was made forbidden, or that the question was asked regarding large pools of water which are not rendered impure by these animals drinking from them. The hanafis also say that the narrations contain some weakness, the first contains the narrator Abd al-Rahman bin Zayd, the second contains Dawud bin Husain, he was weakened by Ibn Hibban and Ibn Abi Habibah, and also weakened by al-Darqutni in al-Sunan. See Fath Bab al-Inayah (1/103)
 Because it does not avoid filth. The karaha here is tanzihi, even though when karaha is mentioned alone it usually refers to tahrimi as is the practise of the hanafi scholars.
 Meaning its leftovers are not disliked for a poor person to eat. Included in this are the likes of bread and other food items which may come in contact with them as they are not free of its saliva. This however does not apply to the left over food items which have not come into contact with their saliva as opposed to water as clarified in ‘al-Hilyah’. The author also indicates to it being disliked for a rich person because he can find other than it. This is when it is thought that its beak is filthy. See Hashiyah Ibn Abidin (1/225).
 The cause for the remnants of donkeys being doubtful is the conflicting evidences regarding the permissibility of consuming its meat. There are narrations which indicate to it being permissible, and narrations which state indicate the opposite. When there was a conflict of evidences the hanafis chose that the remnant being purifying was doubtful, also with the mule being born from a donkey it takes its ruling. See Fath Bab al-Inayah (1/107).