"I heard the Messenger of Allah being asked about water in the wilderness that is frequented by beasts and predators. The Messenger of Allah said: "If the water reaches the amount of two Qullah, nothing can make it impure (Najis).'" (Sahih)

Another chain with similar wording.
Sunan Ibn Majah Book 1, Hadith 251
← Previous Hadith "I saw Sa'ib bin Yazid sniffing his garment, and I said: 'Why (are you doing) that?' He said: 'I heard the Messenger of Allah say: "No ablution (is needed) unless there is an odor or a sound."

Sunan Ibn Majah Book 1, Hadith 250 Next Hadith → "The Messenger of Allah said: 'If the water is the amount of two or three Qullah, nothing can make it impure (Najis).'" (Sahih)

Another chain with similar wording.

Sunan Ibn Majah Book 1, Hadith 252