Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
muslim:1490c – Abū Ghassān al-Mismaʿī And Muḥammad b. al-Muthanná > ʿAbd al-Wahhāb > Yaḥyá b. Saʿīd > Nāfiʿ > Ṣafiyyah b. Abū ʿUbayd

" She should abstain from adorning herself (in case of the death of her husband) for four months and ten days."  

مسلم:١٤٩٠c – وَحَدَّثَنَاهُ أَبُو غَسَّانَ الْمِسْمَعِيُّ وَمُحَمَّدُ بْنُ الْمُثَنَّى قَالاَ حَدَّثَنَا عَبْدُ الْوَهَّابِ قَالَ سَمِعْتُ يَحْيَى بْنَ سَعِيدٍ يَقُولُ سَمِعْتُ نَافِعًا يُحَدِّثُ عَنْ صَفِيَّةَ بِنْتِ أَبِي عُبَيْدٍ

أَنَّهَا سَمِعَتْ حَفْصَةَ بِنْتَ عُمَرَ زَوْجَ النَّبِيِّ ﷺ تُحَدِّثُ عَنِ النَّبِيِّ ﷺ بِمِثْلِ حَدِيثِ اللَّيْثِ وَابْنِ دِينَارٍ وَزَادَ فَإِنَّهَا تُحِدُّ عَلَيْهِ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا  

See similar narrations below:

Collected by Nasāʾī, Nasāʾī's Kubrá
nasai:3503 – Muḥammad b. Bashhār > ʿAbd al-Wahhāb > Nāfiʿ > Ṣafiyyah b. Abū ʿUbayd

"It is not permissible for a woman who believes in Allah and the Last Day to mourn for anyone who dies for more than three days except for a husband; she should mourn for him for four months and ten (days)."  

النسائي:٣٥٠٣ – أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ قَالَ حَدَّثَنَا عَبْدُ الْوَهَّابِ قَالَ سَمِعْتُ نَافِعًا يَقُولُ عَنْ صَفِيَّةَ بِنْتِ أَبِي عُبَيْدٍ

أَنَّهَا سَمِعَتْ حَفْصَةَ بِنْتَ عُمَرَ زَوْجَ النَّبِيِّ ﷺ عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَحِلُّ لاِمْرَأَةٍ تُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ تَحِدُّ عَلَى مَيِّتٍ فَوْقَ ثَلاَثٍ إِلاَّ عَلَى زَوْجٍ فَإِنَّهَا تَحِدُّ عَلَيْهِ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا  

nasai-kubra:5666 – Muḥammad b. Bashhār > ʿAbd al-Wahhāb > Yaḥyá > Ibn Saʿīd al-Anṣārī > Nāfiʿ > Ṣafiyyah b. Abū ʿUbayd

"It is not permissible for a woman who believes in Allah and the Last Day to mourn for anyone who dies for more than three days except for a husband; she should mourn for him for four months and ten (days)." (Using translation from Nasāʾī 3503)  

الكبرى للنسائي:٥٦٦٦ – أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ قَالَ حَدَّثَنَا عَبْدُ الْوَهَّابِ قَالَ سَمِعْتُ يَحْيَى هُوَ ابْنُ سَعِيدٍ الْأَنْصَارِيُّ قَالَ سَمِعْتُ نَافِعًا يَقُولُ عَنْ صَفِيَّةَ بِنْتِ أَبِي عُبَيْدٍ

أَنَّهَا سَمِعَتْ حَفْصَةَ بِنْتَ عُمَرَ زَوْجَ النَّبِيِّ ﷺ عَنِ النَّبِيِّ ﷺ قَالَ «لَا يَحِلُّ لِامْرَأَةٍ تُؤْمِنُ بِاللهِ وَالْيَوْمِ الْآخِرِ أَنْ تُحِدَّ فَوْقَ ثَلَاثٍ إِلَّا عَلَى زَوْجٍ فَإِنَّهَا تُحِدُّ عَلَيْهِ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا»