Sahih Muslim , Book 9, Hadith 3543 (USC-MSA) ⓘ
Zainab bint Abu Salama reported: Umm Salama and Umm Habiba (Allah be pleased with them) were talking with each other (and saying) that a woman came to Allah's Messenger and mentioned to him that her daughter had lost her husband, and her eyes were sore and she wnted to use collyrium, whereupon Allah's Messenger said: One among you used to throw dung at the end of a year, and now (this abstinence from adornment) is only for four months and ten days.
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَمْرٌو النَّاقِدُ، قَالاَ حَدَّثَنَا يَزِيدُ بْنُ هَارُونَ، أَخْبَرَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ حُمَيْدِ بْنِ نَافِعٍ، أَنَّهُ سَمِعَ زَيْنَبَ بِنْتَ أَبِي سَلَمَةَ، تُحَدِّثُ عَنْ أُمِّ سَلَمَةَ، وَأُمِّ حَبِيبَةَ تَذْكُرَانِ أَنَّ امْرَأَةً أَتَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم فَذَكَرَتْ لَهُ أَنَّ بِنْتًا لَهَا تُوُفِّيَ عَنْهَا زَوْجُهَا فَاشْتَكَتْ عَيْنُهَا فَهْىَ تُرِيدُ أَنْ تَكْحُلَهَا فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " قَدْ كَانَتْ إِحْدَاكُنَّ تَرْمِي بِالْبَعَرَةِ عِنْدَ رَأْسِ الْحَوْلِ وَإِنَّمَا هِيَ أَرْبَعَةُ أَشْهُرٍ وَعَشْرٌ " .
also referenced under: Book 18, Hadith 78 (In-Book) & Hadith 1486 (Reference)