Musnad Aḥmad Ḥadīth [543] – The Shyness of ‘Uthmān ibn ‘Affān
It is reported on the authority of al-Ḥasan [al-Baṣrī] that he mentioned 'Uthmān's extreme shyness and said: ‘If he was in a room with the door closed, and he took off his garment to pour water on himself, shyness prevented him from standing up straight.’