A woman came to the Messenger of Allah ﷺ and said, "Messenger of Allah, my daughter's husband has died and her eyes are troubling her. May we apply kohl to them?"The Messenger of Allah ﷺ said, "No," two or three times, each time saying no. Then he said, "It is only four months and ten days. In the days of ignorance, one of you would not throw away the dung pellet until a full year had passed."
قالت زينب وسمعت أمي
جاءت امرأة إلى رسول الله ﷺ فقالت يا رسول الله إن ابنتي توفي عنها زوجها وقد اشتكت عينيها أفنكحلها فقال رسول الله ﷺ لا مرتين أو ثلاث مرات كل ذلك يقول لا ثم قال إنما هي أربعة أشهر وعشرا وقد كانت إحداكن في الجاهلية ترمي بالبعرة على رأس الحول
Agreed upon [by Bukhari and Muslim]. Bukhari narrated it, no. 5336, and Muslim, no. 1488 (see the previous hadith). On this subject there are also narrations from Furayah bint Malik bin Sinan [coming up: 1204] and Hafsa bint Umar [Tayalisi in his Musnad, no. 1587, on the ruling that a woman should not observe mourning for more than three days except for her husband].