كتاب الصلاة
4  
The Book of Prayers
(47)
Chapter: The Sutrah (Screen) For One Who Is Praying, And The Recommendation To Pray Facing A Sutrah. The Ruling On Passing In Front Of One Who Is Praying, And Preventing One Who Wants To Pass In Front. It Is Permissible To Lie Down In Front Of One Who Is Praying, Praying Towards One's Mount. The Command To Stand Close To The Sutrah. The Height Of The Suirah, And Related Matters
(47)
باب سُتْرَةِ الْمُصَلِّي ‏
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 ‏.‏
Reference : Sahih Muslim 503e
In-book reference : Book 4, Hadith 285
USC-MSA web (English) reference : Book 4, Hadith 1018
  (deprecated numbering scheme)