It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he said: "When the Messenger of Allah (peace and blessings be upon him) conquered Makkah, and Sayyiduna Abu Bakr (may Allah be pleased with him) was standing by his head, he said: 'O Messenger of Allah, may my father and mother be ransomed for you! Abu Quhafah is a very old man, and he is in a corner of Makkah.' The Messenger of Allah (peace and blessings be upon him) said: 'Come with us to him.' He said: 'O Messenger of Allah, he is more deserving that he should come to you himself.' So Sayyiduna Abu Quhafah (may Allah be pleased with him) was brought, (and his state was such) that his head and beard were completely white, like the thaghamah (a white-flowering plant). The Messenger of Allah (peace and blessings be upon him) said: 'Change it (this whiteness), and keep it away from black.'"
Hadith Referenceالمعجم الأوسط / باب العين / 4568
Hadith Gradingمحدثین:إسناده ضعيف، فيه داود بن فراهيج مختلف فيه ومن لم يعرفهم الهيثمي
Hadith Takhrij«قال الهيثمي: وفيه داود بن فراهيج وثقه يحيى القطان وغيره وضعفه جماعة وفيه من لم أعرفهم «مجمع الزوائد ومنبع الفوائد، ج 5، ص 161»»