Muwatta Malik #1323

Yahya related to me from Malik from Nafi from Safiyya bint Abi Ubayd from A'isha and Hafsa, the wives of the Prophet, may Allah bless him and grant him peace, that the Messenger of Allah, may Allah bless him and grant him peace, said, "It is not halal for a woman in mourning for someone who has died, if she trusts in Allah and the Last Day, to abstain from adornment for more than three nights, except for a husband."