The Messenger of Allah ﷺ was asked about water and the animals and beasts that come to it. The Messenger of Allah ﷺ replied, "When the water reaches two qullahs, it does not carry impurity."
حدثنا محمد بن العلاء وعثمان بن أبي شيبة والحسن بن علي وغيرهم قالوا حدثنا أبو أسامة عن الوليد بن كثير عن محمد بن جعفر بن الزبير
سئل رسول الله ﷺ عن الماء وما ينوبه من الدواب والسباع فقال ﷺ إذا كان الماء قلتين لم يحمل الخبث
[Its chain of transmission is sahih]. Nasai narrated it in Taharah, chapter on the fixed measure for water, no. 52, from the hadith of Abu Usama Hammad bin Usama, through this route. Ibn Hibban graded it sahih (Mawarid): 118, and Hakim: 1/132, 133, and others as well.