Hammad bin Usamah حماد بن أسامة - أبو أسامة · The Book of Purification

"The Messenger of Allah (ﷺ) was asked about water and how some animals and carnivorous beasts might drink from it. He said: 'If the water is more than two Qullahs, it will not carry filth.'" It comes with some explanation in Sunan At Timidhi 'Abdah (one of the narrators) said: "Muhammad bin Ishaq said: 'A Qullah refers to Jirar (These are two nouns describing large casks that are used to hold water), and a Qullah is the thing that drinking…

"I noticed the Prophet (ﷺ) was not there one night, so I started looking for him with my hand. My hand touched his feet and they were held upright, and he was prostrating and saying: 'I seek refuge in Your pleasure from Your anger, in Your forgiveness from Your punishment, and I seek refuge in You from You. I cannot praise You enough, You are as You have praised yourself.'"