Narrated Abu Ma'mar:- We asked Khabbab "Did the Prophet (may Allah's peace and blessings be upon him) used to recite (the Quran) in the Thur and the 'Asr prayers. He replied in the affirmative. We said, "How did you come to know this?" He said, "By the movement of his beard." - Reported by Al Bukhari
"Being of those people that are said to be two faced, need to really look into themselves and see if this quality exists. If they find it does, than they need to do their best to remove it so that they can be free from this description that The Messenger of Allah (may Allah's peace and blessings be upon him) described the two faced people as having, which was 'the worst of the people'."