al-Zuhri ابن شهاب الزهري‎, محمد بن مسلم · Combing the Hair (Kitab Al-Tarajjul)

A woman made a sign from behind a curtain to indicate that she had a letter for the Messenger of Allah (ﷺ). The Prophet (ﷺ) closed his hand, saying: I do not know this is a man's or a woman's hand. She said: No, a woman. He said: If you were a woman, you would make a difference to your nails, meaning with henna.

The hair of the Messenger of Allah (ﷺ) were above wafrah and below jummah.

Al-Hajjaj ibn Hassan said: We entered upon Anas ibn Malik. My sister al-Mughirah said: You were a boy in those days and you had two locks of hair. He (Anas) rubbed your head and invoked blessing on you. He said: Shave them (i.e. the locks) or clip them, for this is the fashion of the Jews.

Do not pluck out grey hair. If any believer grows a grey hair in Islam, he will have light on the Day of Resurrection. (This is Sufyan's version). Yahya's version says: Allah will record on his behalf a good deed for it, and will blot out a sin for it.