Anas Radiyallahu 'Anhu reports:
"The day Nabi Sallallahu 'Alayhi Wasallam came to Madinah, everything in Madinah became illuminated. (When the anwaar increased, it could be felt. In the dark nights of Ramadaan many a time because of the intensity of the anwaaraat (illuminations), a natural illumination, was felt). The day when Rasulullah Sallallahu 'Alayhi Wasallam passed away, 'everything of Madinah became dark. We had not yet dusted off the dust from our hands after the burial of Rasulullah Sallallahu 'Alayhi Wasallam when we began to feel the change in our hearts."
English reference: Book 53, Hadith 375
Arabic reference: Book 54, Hadith 392