Muwatta Imam Malik Book of Divorce, Hadith 104

Yahya related to me from Malik from Nafi from Safiyya bint Abi Ubayd from A'isha and Hafsa, the wives of the Prophet ﷺ that the Messenger of Allah ﷺ 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."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ صَفِيَّةَ بِنْتِ أَبِي عُبَيْدٍ، عَنْ عَائِشَةَ، وَحَفْصَةَ، زَوْجَىِ النَّبِيِّ ﷺ أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ