Narrated Abu Ma`mar: We asked Khabbab whether Allah's Apostle used to recite (the Qur'an) in the Zuhr and the `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."
Hadith ReferenceSahih Bukhari / The Book of Adhan (Sufa-tus-Salat) / Hadith: 746
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة