Sunan an-Nasa'i #328 · The Book of Water

Sunan an-Nasa'iIt was narrated from 'Ubaidullah bin 'Abdullah bin 'Umar that his father said
Sunan an-Nasa'i · Book 2 · The Book of Water
Sunan an-Nasa'i · كتاب 2 · كتاب المياه
"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 become filthy
أَخْبَرَنَا الْحُسَيْنُ بْنُ حُرَيْثٍ الْمَرْوَزِيُّ، قَالَ حَدَّثَنَا أَبُو أُسَامَةَ، عَنِ الْوَلِيدِ بْنِ كَثِيرٍ، عَنْ مُحَمَّدِ بْنِ جَعْفَرِ بْنِ الزُّبَيْرِ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُمَرَ، عَنْ أَبِيهِ، قَالَ سُئِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ الْمَاءِ وَمَا يَنُوبُهُ مِنَ الدَّوَابِّ وَالسِّبَاعِ فَقَالَ ‏
"‏ إِذَا كَانَ الْمَاءُ قُلَّتَيْنِ لَمْ يَحْمِلِ الْخَبَثَ ‏"‏ ‏.‏
Reference : Sunan an-Nasa'i 328In-book reference : Book 2, Hadith 4