Sahih
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا الأَعْمَشُ، عَنْ عُمَارَةَ بْنِ عُمَيْرٍ، عَنْ أَبِي مَعْمَرٍ، قَالَ قُلْتُ لِخَبَّابٍ بِأَىِّ شَىْءٍ كُنْتُمْ تَعْرِفُونَ قِرَاءَةَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فِي الظُّهْرِ وَالْعَصْرِ قَالَ بِاضْطِرَابِ لِحْيَتِهِ .
It was narrated that Abu Ma’mar said:“I said to Khabbab: ‘How did you recognize that the Messenger of Allah (ﷺ) was reciting in the Zuhr and the ‘Asr?’ He said: ‘From the movement of his beard.’”