Sayyiduna Anas (may Allah be pleased with him) said: the Prophet (peace and blessings be upon him) came to us and lay down to rest, and he (peace and blessings be upon him) began to sweat. Umm Sulaym (may Allah be pleased with her) brought a small bottle and began collecting the sweat in it. The Prophet (peace and blessings be upon him) woke up and said: "O Umm Sulaym! What are you doing?" She said: "This is your sweat; we mix it into our perfume, and it is the finest of perfumes."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21751