'Aayeshah Radiyallahu 'Anha reports:
(because of the excessive modesty of Sayyidina Rasulullah Sallallahu 'Alayhi Wasallam) "I did not have the courage to see the private parts of Rasulullah Sallallahu'Alayhi Wasallam, or that I never saw the private parts of Rasulullah Sallallahu 'Alayhi Wasallam".
English reference: Book 48, Hadith 342
Arabic reference: Book 49, Hadith 359