Musnad Ahmad Hadith 13366

It is narrated from Anas (may Allah be pleased with him) that the Prophet (ﷺ) used to come to the house of Umm Sulaym (may Allah be pleased with her) and sleep on her bed, and she would not be there. One day, as usual, the Prophet (ﷺ) came and slept on her bed. Someone went and told her that the Prophet (ﷺ) is sleeping in your house on your bed. So she came home and saw that the Prophet (ﷺ) was drenched in sweat, and that sweat was falling onto a piece of leather spread on the bed. She opened her scarf and began to soak up the sweat with it and squeeze it into a bottle. The Prophet (ﷺ) woke up startled and said, "Umm Sulaym! What are you doing?" She replied, "O Messenger of Allah (ﷺ)! We hope for blessings for our children from this." The Prophet (ﷺ) said, "You have done right."