Sunan An-Nasa'i

It was narrated from Anas bin Malik that:The Prophet [SAW] lay down on a leather mat and sweated. Umm Sulaim got up and collected his sweat and put it in a bottle. The Prophet [SAW] saw her and said: ""What are you doing O Umm Sulaim?"" She said: ""I am putting your sweat in my perfume."" And the Prophet [SAW] smiled