Hadith 27:156
Sahih (Darussalam)
It was narrated from Hafsah, from Umm 'Atiyyah, from the Prophet, that he granted a concession to the woman whose husband has died, allowing her to use Qust and Azfar when purifying herself following her menses.
أَخْبَرَنَا الْعَبَّاسُ بْنُ مُحَمَّدٍ، - هُوَ الدُّورِيُّ - قَالَ حَدَّثَنَا الأَسْوَدُ بْنُ عَامِرٍ، عَنْ زَائِدَةَ، عَنْ هِشَامٍ، عَنْ حَفْصَةَ، عَنْ أُمِّ عَطِيَّةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم أَنَّهُ رَخَّصَ لِلْمُتَوَفَّى عَنْهَا عِنْدَ طُهْرِهَا فِي الْقُسْطِ وَالأَظْفَارِ
Original Reference: Sunan an-Nasa'i 3542