Sahih Muslim
The Book on Government (Kitab Al-Imara)
Book Number: 020 / Hadith Number: 4603
It has been narrated on the authority of 'Urwa that 'A'isha described to him the way the Holy Prophet (may peace be upon him) took the oath of fealty from women. She said: The Messenger of Allah (may peace be upon him) never touched a woman with his hand. He would only take a vow from her and when he had taken the (verbal) vow, he would say: You may go. I have accepted your fealty.