The Prophet was asked about the water basins located between Makkah and Al-Madinah, which were visited by wild animals, dogs and donkeys, and about using them for means of purification. He said: "Whatever they (the animals) have carried in their bellies is for them, and whatever is left over is for us, and is pure."  

أَنَّ النَّبِيَّ ﷺ سُئِلَ عَنِ الْحِيَاضِ الَّتِي بَيْنَ مَكَّةَ وَالْمَدِينَةِ تَرِدُهَا السِّبَاعُ وَالْكِلاَبُ وَالْحُمُرُ وَعَنِ الطَّهَارَةِ مِنْهَا فَقَالَ لَهَا مَا حَمَلَتْ فِي بُطُونِهَا وَلَنَا مَا غَبَرَ طَهُورٌ  

"We came to a pond in which there was the carcass of a donkey, so we refrained from using the water until the Messenger of Allah came to us and said: 'Water is not made impure by anything.' Then we drank from it and gave it to our animals to drink, and we carried some with us."  

انْتَهَيْنَا إِلَى غَدِيرٍ فَإِذَا فِيهِ جِيفَةُ حِمَارٍ قَالَ فَكَفَفْنَا عَنْهُ حَتَّى انْتَهَى إِلَيْنَا رَسُولُ اللَّهِ ﷺ فَقَالَ إِنَّ الْمَاءَ لاَ يُنَجِّسُهُ شَىْءٌ فَاسْتَقَيْنَا وَأَرْوَيْنَا وَحَمَلْنَا  

"The Messenger of Allah said: 'Water is not made impure by anything except that which changes its smell, taste and color.'"  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ الْمَاءَ لاَ يُنَجِّسُهُ شَىْءٌ إِلاَّ مَا غَلَبَ عَلَى رِيحِهِ وَطَعْمِهِ وَلَوْنِهِ