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

Yahya related to me from Malik from Nafi from Safiyya bint AbiUbayd from A'isha and Hafsa, the wives of the Prophet, may Allah blesshim and grant him peace, that the Messenger of Allah, may Allah blesshim and grant him peace, said, "It is not halal for a woman inmourning for someone who has died, if she trusts in Allah and the LastDay, to abstain from adornment for more than three nights, except fora husband." Translation Not Available

Book Ref: Muwatta Imam Malik Book 29 Hadith 1269
Web Ref:  Muwatta Imam Malik Book 29 Hadith 104