كتاب الطهارة
2  
The Book of Purification
(22)
Chapter: Wiping over the khuff (leather socks)
(22)
باب الْمَسْحِ عَلَى الْخُفَّيْنِ ‏‏
Sahih Muslim 274b

This hadith has been transmitted with the same chain of transmitters by Yahya b. Sa'id with the addition of these words:

" He washed his face and hands, and wiped his head and then wiped his socks."
وَحَدَّثَنَاهُ مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ، بِهَذَا الإِسْنَادِ وَقَالَ فَغَسَلَ وَجْهَهُ وَيَدَيْهِ وَمَسَحَ بِرَأْسِهِ ثُمَّ مَسَحَ عَلَى الْخُفَّيْنِ ‏.‏
Reference : Sahih Muslim 274b
In-book reference : Book 2, Hadith 94
USC-MSA web (English) reference : Book 2, Hadith 525
  (deprecated numbering scheme)