Wiping over the khuff (leather 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 .
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."