Bukhari 761

From Sahih Bukhari (Hadith 761):

Narrated Abu Ma`mar:I asked Khabbab bin Al-Art whether the Prophet (ﷺ) used to recite the Qur'an in the Zuhr and the `Asr prayers. He replied in the affirmative. I said, "How did you come to know that?" He replied, "From the movement of his beard