Sahih Bukhari Volume 2, Book 11, Hadith 903

حَدَّثَنَا أَحْمَدُ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، قَالَ أَخْبَرَنِي عَمْرُو بْنُ الْحَارِثِ، عَنْ عُبَيْدِ اللَّهِ بْنِ أَبِي جَعْفَرٍ، أَنَّ مُحَمَّدَ بْنَ جَعْفَرِ بْنِ الزُّبَيْرِ، حَدَّثَهُ عَنْ عُرْوَةَ بْنِ الزُّبَيْرِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ صلى الله عليه وسلم قَالَتْ كَانَ النَّاسُ يَنْتَابُونَ يَوْمَ الْجُمُعَةِ مِنْ مَنَازِلِهِمْ وَالْعَوَالِي، فَيَأْتُونَ فِي الْغُبَارِ، يُصِيبُهُمُ الْغُبَارُ وَالْعَرَقُ، فَيَخْرُجُ مِنْهُمُ الْعَرَقُ، فَأَتَى رَسُولَ اللَّهِ صلى الله عليه وسلم إِنْسَانٌ مِنْهُمْ وَهْوَ عِنْدِي، فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ لَوْ أَنَّكُمْ تَطَهَّرْتُمْ لِيَوْمِكُمْ هَذَا ‏"‏‏

Narrated By 'Aisha : (The wife of the Prophet) The people used to come from their abodes and from Al-'Awali (i.e. outskirts of Medina up to a distance of four miles or more from Medina). They used to pass through dust and used to be drenched with sweat and covered with dust; so sweat used to trickle from them. One of them came to Allah's Apostle who was in my house. The Prophet said to him, "I wish that you keep yourself clean on this day of yours (i.e. take a bath)."