Sahih Muslim 503 e
Shu'ba narrated the same on the basis of two authorities and in the hadith transmitted by Hakam (the words are):
The people began to get water that was left out of his (the Prophet's) ablution.
وَحَدَّثَنِي زُهَيْرُ بْنُ حَرْبٍ، وَمُحَمَّدُ بْنُ حَاتِمٍ، قَالاَ حَدَّثَنَا ابْنُ مَهْدِيٍّ، حَدَّثَنَا شُعْبَةُ، بِالإِسْنَادَيْنِ جَمِيعًا مِثْلَهُ ‏.‏ وَزَادَ فِي حَدِيثِ الْحَكَمِ فَجَعَلَ النَّاسُ يَأْخُذُونَ مِنْ فَضْلِ وَضُوئِهِ ‏.‏