عَنِ الْمُغِيرَةِ بْنِ شُعْبَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّهُ قَالَ: خَصْلَتَانِ لَا أَسْأَلُ عَنْهُمَا أَحَدًا مِنَ النَّاسِ، رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ فَعَلَهُمَا، صَلَاةُ الْإِمَامِ خَلْفَ الرَّجُلِ مِنْ رَعِيَّتِهِ، وَقَدْ رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ خَلْفَ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ رَكْعَةً مِنْ صَلَاةٍ الصُّبْحِ وَمَسْحُ الرَّجْلِ عَلَى خُفَّيْهِ وَقَدْ رَأَيْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَمْسَحُ عَلَى الْخُفَّيْنِ
Sayyiduna Mughirah bin Shu’bah (may Allah be pleased with him) says: There are two qualities regarding which I will not ask anyone among the people, because I myself have seen the Messenger of Allah (peace and blessings be upon him) performing both actions. (1) The Imam performing prayer behind one of his subjects; indeed, I saw the Messenger of Allah (peace and blessings be upon him) perform one rak’ah of Fajr prayer following Sayyiduna Abdur Rahman bin Awf (may Allah be pleased with him), and (2) a man wiping over his leather socks (khuffs); indeed, I saw the Messenger of Allah (peace and blessings be upon him) wiping over his leather socks.