It was narrated from Humaid bin Nafi' that:
he heard Zainab the daughter of Umm Salamah narrating that she heard Umm Salamah and Umm Habibah mention that a woman came to the Prophet (ﷺ) and said that her daughter's husband had died, and she was suffering from an eye disease, and she wanted to apply kohl to her eyes (as a remedy). The Messenger of Allah (ﷺ) said: "One of you would throw a she-camel's dropping when a year had passed (since the death of her husband. Rather it is four months and ten (days)."
English reference: Vol. 3, Book 10, Hadith 2084
Arabic reference: Book 10, Hadith 2162