Sahih Ibn Khuzaymah

Hazrat Al-Muntashir narrates that he asked Sayyiduna Ibn Umar (may Allah be pleased with them both) about applying perfume at the time of Ihram, so he replied: If I were to apply tar (a foul-smelling oil similar to pitch, which is applied to mangy camels) to my body, in my view, this would be better than applying perfume at the time of Ihram. Hazrat Al-Muntashir says that I told this statement of his to Sayyidah Aisha (may Allah be pleased with her), so she said: May Allah have mercy on Abu Abdur Rahman (he does not know this issue). I myself used to apply perfume to the Messenger of Allah (peace and blessings be upon him), then he would have intercourse with his wives, then in the morning he would enter into Ihram, while the fragrance would be emanating from his blessed body.

Imam Rabi’ says that Imam Shafi’i (may Allah have mercy on him) was asked about a fly that, after sitting on filth, comes flying and sits on a person’s clothes, so what should that person do? He replied: If its legs had dried in the air while flying, then there is no harm. And if they were still wet, even then there is no harm, because when there is extreme difficulty and hardship in a matter, then Islam gives concession and ease in it. (That is, when it becomes difficult to avoid such a fly, then such a small amount of impurity is excused.)