حَدَّثَنَا حَيْوَةُ بْنُ شُرَيْحٍ، حَدَّثَنَا بَقِيَّةُ، عَنْ بَحِيرٍ، - هُوَ ابْنُ سَعْدٍ - عَنْ خَالِدٍ، عَنْ بَعْضِ، أَصْحَابِ النَّبِيِّ أَنَّ النَّبِيَّ صلى الله عليه وسلم رَأَى رَجُلاً يُصَلِّي وَفِي ظَهْرِ قَدَمِهِ لُمْعَةٌ قَدْرُ الدِّرْهَمِ لَمْ يُصِبْهَا الْمَاءُ فَأَمَرَهُ النَّبِيُّ صلى الله عليه وسلم أَنْ يُعِيدَ الْوُضُوءَ وَالصَّلاَةَ ‏.‏

Narrated Some Companions of the Prophet: The Prophet (PBUH) saw a person offering prayer, and on the back of his foot a small part equal to the space of a dirham remained unwashed; the water did not reach it. The Prophet (PBUH) commanded him to repeat the ablution and prayer. Translation Not Available

Book Ref: Sunan Abi Dawud Book 1 Hadith 175
Web Ref:  Sunan Abi Dawud Book 1 Hadith 175

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