Hello, I would like to ask about part of the description of the battle of Yarmuk: “When the news of his death was carried to his daughter, Umm Habeebah, she waited until the third day, on which she ordered some yellow paint and covered with it her arms and face, saying, ‘I would not have done that had I not heard the Prophet say, 'A woman should not be in mourning for more than three days over anyone except her husband.'’”
Could you explain to me why Umm Habeebah covered her arms and face with yellow paint? What does that mean? Why did she use yellow paint?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

Al-Bukhaari and Muslim narrated in their Saheeh from Zaynab bint Abu Salamah that she said:

“When the news of the death of Abu Sufyaan arrived from Ash-Shaam (Greater Syria), Umm Habeebah, may Allah be pleased with her, asked on the third day for a yellow perfume and scented her cheeks and forearms and said, ‘No doubt, I would not have been in need of this had I not heard the Prophet say, 'It is not lawful for a woman who believes in Allah and the Last Day to mourn for more than three days for any dead person except for her husband, for whom she should mourn for four months and ten days.'’”

Umm Habeebah, may Allah be pleased with her, did so – wore perfume – on the third day so that she would not commit what the Prophet forbade, which is to mourn anyone other than the husband for more than three days. A woman is required to mourn her husband for four months and ten days. The meaning of mourning is that she refrains from wearing perfume and adorning herself (with makeup or the like) until the end of her waiting period (‘Iddah) after the death of her husband. However, she is not permitted to mourn anyone other than her husband more than three days, as she herself narrated from the Prophet at the end of the hadeeth. Therefore, she does not mourn her father or her brother or other relatives if they die more than three days. It is for this reason that she took perfume on the third day and applied it on herself, and she indicated that she did not desire to wear perfume but only did so lest she commits what the Prophet had forbidden.

The perfume that she applied is called Sufrah or Khalooq, as in another narration. Sufrah is the yellow effect of saffron. Khalooq is a known perfume made from saffron and other perfumes, but it is mostly reddish and yellowish, and it is a perfume that is peculiar to women.

Allah knows best.