Sahih Muslim Book 20, Hadith Number 4603.

Chapter : How the women swore fealty (to the Holy Prophet).

It has been narrated on the authority of ‘Urwa that ‘Aisha 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.