Maliks Muwatta Book 29, Hadith Number 101.
Yahya related to me from Malik from Abdullah ibn Abi Bakr ibn Muhammad ibn Amr ibn Hazm from Humayd ibn Nafi that Zaynab bint Abi Salama related these three traditions to him. Zaynab said, “I visited Umm Habiba, the wife of the Prophet, may Allah bless him and grant him peace, when her father Abu Sufyan ibn Harb had died. Umm Habiba called for a yellowy perfume perhaps khaluq or something else. She rubbed the perfume first on a slave-girl and she then wiped it on the sides of her face and said, ‘By Allah! I have no need of perfume but I heard the Messenger of Allah, may Allah bless him and grant him peace, say, ‘It is not halal for a woman who trusts in Allah and the Last Day to abstain from adornment in mourning for someone who has died, for more than three nights, except for four months and ten days for a husband.'”