Hadith 279
Hazrat Qasim bin Muhammad (may Allah have mercy on him) narrates that I asked Sayyida Aisha (may Allah be pleased with her) about a man who goes to his wife (has intercourse with her), then puts on his clothes and sweats in them, do they become impure? She replied that a woman used to keep a piece or pieces of old cloth, and when this happened (i.e., when the man had intercourse), the man would clean the impurity with that piece, and he did not think that (due to the sweat) his clothes would become impure.
Hadith 280
The noble wife of the Prophet Muhammad (peace be upon him), Sayyidah Aisha (may Allah be pleased with her), narrates that a woman should keep a piece of old cloth, then when her husband finishes (intercourse), she should give it to him, he should clean the impurity from his body, and the woman should also clean herself, then both of them (after performing ghusl) may pray in those same clothes.