Musannaf Ibn Abi Shaybah

Hazrat Taliq bin Habib narrates that a barber trimmed the mustache of the Noble Prophet (peace and blessings be upon him). He saw a white hair in the beard of the Noble Prophet (peace and blessings be upon him) and wanted to cut it, but the Messenger of Allah (peace and blessings be upon him) held his hand and said: Whoever grows old while adhering to Islam, for him there will be a light on the Day of Resurrection.