And the explanation of the evidence that the Prophet (peace be upon him) did not mean all water by his statement "Nothing makes water impure," but rather he meant some types of water. The water he (peace be upon him) meant is that which is « قلتين » or more; he (peace be upon him) did not mean water less than « قلتين » "two pitchers."
Hadith Referenceصحيح ابن خزيمه / جماع أبواب ذكر الماء الذي لا ينجس، والذي ينجس إذا خالطته نجاسة / Q92
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings of Allah be upon him) was asked about the water upon which cattle and wild animals come and go (to drink). The Messenger of Allah (peace and blessings of Allah be upon him) said: "When the water is two pitchers, it does not become impure." This is the narration of Mu’thirah. Musa bin Abdur Rahman, in his narration, has mentioned « عن » instead of « حدث ». And instead of « لم يَحْمِلْالخُبَثَ », he has stated the words « لَميُنْجِسْهُشَيٌءُٗ » "Nothing makes it impure." (The Imam says) Mukhrami has narrated to us a concise narration, and said that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When the water is two pitchers, it does not become impure." He did not mention the question to the Prophet (peace and blessings of Allah be upon him) about water and the birds and cattle that come and go upon it.
Hadith Referenceصحيح ابن خزيمه / جماع أبواب ذكر الماء الذي لا ينجس، والذي ينجس إذا خالطته نجاسة / 92
Hadith Takhrij«اسناده صحيح: ارواء الغليل: 23 ، صحيح ابي داود: 59 ، 56 ، سنن الترمذي: كتاب الطهارة: باب منه أخر ، رقم الحديث: 67 ، سنن ابن ماجه: 517 ، سنن الدارمي: 732 ، و سنن نسائي: 52 ، والبيهقي فى الكبرىٰ: رقم: 1162»