Call to Prayers (Adhaan)
Bukhari :: Book 1 :: Volume 11 :: Hadith 599
Allah's Apostle used to pray two light Rakat before the morning (compulsory) prayer after the day dawned and the Mu'adhdhin had finished his Adhan. He then would lie on his right side till the Mu'adhdhin came to pronounce the Iqama.
Source materials are from the University of Southern California MSA site|
Hadith eBooks converted from Imaan Star