Silsilat al-Ahadith al-Sahihah

Sayyiduna Abu Umamah (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings of Allah be upon him) came to some Ansaris with white beards and said: "O group of Ansaris! (Color your white hair) red or yellow and oppose the People of the Book." They said: O Messenger of Allah! Indeed, the People of the Book trim their beards and grow their mustaches. The Messenger of Allah (peace and blessings of Allah be upon him) said: "You grow your beards and trim your mustaches and oppose the People of the Book." They said: O Messenger of Allah! Indeed, the People of the Book wear leather socks and do not wear shoes. He (peace and blessings of Allah be upon him) said: "You wear shoes as well as socks and oppose the People of the Book."