Hadith 2983
Sayyiduna Umar bin Khattab (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings be upon him) said: "Whoever grows old in Islam (i.e., any Muslim whose hair turns white), then this will be a light for him on the Day of Resurrection."
Hadith 2984
Sayyiduna Abu Najeeh Salmi (may Allah be pleased with him) narrates: I heard the Prophet Muhammad (peace and blessings be upon him) say: "Whoever grows old in the way of Allah (i.e., his hair turns white in His cause), then this will be a light for him on the Day of Resurrection."