A woman asked Umm Salamah (may Allah be pleased with her) and Umm Habibah (may Allah be pleased with her): May a woman apply kohl during her waiting period ('iddah) after the death of her husband? One of them said: A woman came to the Prophet (peace and blessings be upon him) and asked him this very question, and he (peace and blessings be upon him) said: "In the time of Ignorance (Jahiliyyah), when the husband of one of you died, she would remain in mourning for a year, then throw a piece of dung; this is only four months and ten days, until the term is completed."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19730