Sunan an-Nasa'i 328
سنن النسائي#328SahihIt was narrated from 'Ubaidullah bin 'Abdullah bin 'Umar that his father said:"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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih
In-book reference: 2:4