Sahih al-Bukhari Book 68, Hadith 82
I (Humaid) said to Zainab, "What does 'throwing a globe of dung when one
year had elapsed' mean?" Zainab said, "When a lady was bereaved of her husband, she would live in a
wretched small room and put on the worst clothes she had and would not touch any scent till one year
had elapsed. Then she would bring an animal, e.g. a donkey, a sheep or a bird and rub her body
against it. The animal against which she would rub her body would scarcely survive. Only then she
would come out of her room, whereupon she would be given a globe of dung which she would throw
away and then she would use the scent she liked or the like."
"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."
A woman was bereaved of her husband and her relatives worried about her eyes (which were diseased). They came to Allah's Messenger (ﷺ), and asked him to allow them to treat her eyes with kohl, but he said, "She should not apply kohl to her eyes. (In the Pre-Islamic period of Ignorance) a widowed woman among you would stay in the worst of her clothes (or the worst part of her house) and when a year had elapsed, if a dog passed by her, she would throw a globe of dung, Nay, (she cannot use kohl) till four months and ten days have elapsed."