Characteristics of Prayer
Bukhari :: Book 1 :: Volume 12 :: Hadith 744
Narrated Abu Ma'mar:
We said to Khabbab "Did Allah's Apostle used to recite in Zuhr and 'Asr prayers?" He replied in the affirmative. We said, "How did you come to know about it?" He said, "By the movement of his beard."
Source materials are from the University of Southern California MSA site|
Hadith eBooks converted from Imaan Star