The Messenger of Allah (ﷺ) prohibited drinking by inverting the heads of skin vessels.
Sunan Abi Dawud Book 27, Hadith 52
← Previous Hadith The apostle of allah (ﷺ) forbade drinking from the mouth of a water-skin, and riding the animal which feeds on filth and eating the animal which is killed in confinement.

Abu Dawud said: Jallalah means an animal which eats filth and impurities.

Sunan Abi Dawud Book 27, Hadith 51 Next Hadith → Invert the head of the vessel and he drank from its mouth.

Sunan Abi Dawud Book 27, Hadith 53