We asked Khabbab, "Did the Messenger of Allah ﷺ recite in the Dhuhr and Asr prayers?"He replied, "Yes."We asked, "How could you tell?"He answered, "By the movement of his beard."
قلنا لخبآب: أكان رسول الله ﷺ يقرأ في الظهر والعصر؟ قال: نعم، قلنا: بم كنتم تعرفون ذلك؟ قال: باضطراب لحيته.
Bukhari narrated it in the Book of Adhan (746) via Amash, who said, I heard Umara bin Umayr narrating from Abu Muamar, who said, and then he mentioned the hadith. Abu Muamar is Abdullah bin Sakhbarah, with the first letter unpointed and vowelled with fatha, the second letter dotted and vowelled with sukun, and the third letter vowelled with fatha, the Azdi, the Kufan.