(Imām Bukhārī narrates): Mūsā narrated to us, he said: 'Abdul-Wāhid narrated to us, he said: Al-A'mash narrated to us, from 'Umārah ibn 'Umair, from Abī Ma'mar, he narrates that:

we asked Khabbāb, may Allāh be pleased with him: Did the Messenger of Allāh ﷺ recite in the Zuhr and 'Asr prayers? He said: Yes. We said: By what did you recognize that? He said: By the movement of his beard.