(46) باب تُحِدُّ الْمُتَوَفَّى عَنْهَا زَوْجُهَا أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا
Zainab further said:
"I heard my mother, Um Salama saying that a woman came to Allah's Messenger (ﷺ) and said, "O Allah's Messenger (ﷺ)! The husband of my daughter has died and she is suffering from an eye disease, can she apply kohl to her eye?" Allah's Messenger (ﷺ) replied, "No," twice or thrice. (Every time she repeated her question) he said, "No." Then Allah's Messenger (ﷺ) added, "It is just a matter of four months and ten days. In the Pre-Islamic Period of ignorance a widow among you should throw a globe of dung when one year has elapsed."
Reference: Sahih al-Bukhari 5336
In-book reference: Book 68, Hadith 81
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 63, Hadith 251