Sahih Muslim 339 c
Abu Huraira reported that Moses was a modest person. He was never seen naked and Banu Isra'iI said:
(He was afraid to expose his private part) because he had been suffering from scrotal hernia. He (one day) took bath in water and placed his garments upon a stone. The stone began to move on quickly. He followed that and struck it with the help of a stone (saying): O stone, my garment; O stone, my garments, O stone; until it stopped near the big gathering of Isrii'll, and this verse was revealed (pertaining to the incident):" O you who believe, be not Iike those who maligned Moses, but Allah cleared him of what they said, and he was worthy of regard with Allah" (xxxiii. 69).
وَحَدَّثَنَا يَحْيَى بْنُ حَبِيبٍ الْحَارِثِيُّ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، حَدَّثَنَا خَالِدٌ الْحَذَّاءُ، عَنْ 
 عَبْدِ اللَّهِ بْنِ شَقِيقٍ، قَالَ أَنْبَأَنَا أَبُو هُرَيْرَةَ، قَالَ كَانَ مُوسَى عَلَيْهِ السَّلاَمُ رَجُلاً حَيِيًّا -
 قَالَ - فَكَانَ لاَ يُرَى مُتَجَرِّدًا - قَالَ - فَقَالَ بَنُو إِسْرَائِيلَ إِنَّهُ آدَرُ - قَالَ - فَاغْتَسَلَ
 عِنْدَ مُوَيْهٍ فَوَضَعَ ثَوْبَهُ عَلَى حَجَرٍ فَانْطَلَقَ الْحَجَرُ يَسْعَى وَاتَّبَعَهُ بِعَصَاهُ يَضْرِبُهُ ثَوْبِي حَجَرُ
 ثَوْبِي حَجَرُ ‏.‏ حَتَّى وَقَفَ عَلَى مَلإٍ مِنْ بَنِي إِسْرَائِيلَ وَنَزَلَتْ ‏{‏ يَا أَيُّهَا الَّذِينَ آمَنُوا لاَ تَكُونُوا
 كَالَّذِينَ آذَوْا مُوسَى فَبَرَّأَهُ اللَّهُ مِمَّا قَالُوا وَكَانَ عِنْدَ اللَّهِ وَجِيهًا‏}‏