Clothing (Kitab Al-Libas)
Dawud :: Book 32 : Hadith 4095
Narrated Aisha, Ummul Mu'minin:
A mukhannath (eunuch) used to enter upon the wives of Prophet (peace_be_upon_him). They (the people) counted him among those who were free of physical needs. One day the Prophet (peace_be_upon_him) entered upon us when he was with one of his wives, and was describing the qualities of a woman, saying: When she comes forward, she comes forward with four (folds in her stomach), and when she goes backward, she goes backward with eight (folds in her stomach). The Prophet (peace_be_upon_him) said: Do I not see that this (man) knows what here lies. Then they (the wives) observed veil from him.