Sunan Ibn Majah
3623
Sahih+3

It was narrated that ‘Uthman bin Mawhab said:“I entered upon Umm Salamah and she brought out for me a hair of the Messenger of Allah (ﷺ), which was dyed with henna and Katam.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi