It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both), he says: I heard that the Messenger of Allah (peace and blessings be upon him) was asked about the water in the wilderness, over which cattle and wild animals also come. The Messenger of Allah (peace and blessings be upon him) said: "When the water reaches the amount of two qullahs, it does not carry impurity (i.e., it does not accept impurity)."