Sunan Ibn Majah, Chapter: The Chapters on Jihad

the wife of the Prophet (saw) said: "When the believing women emigrated to the Messenger of Allah (saw), they would be tested in accordance with Allah's saying: 'O Prophet! When believing women come to you to give you the pledge...'"[60:12] Aisha said: "Whoever among the believing women affirmed this, passed the test. When they affirmed that, the Messenger of Allah (saw) would say to them: 'Go, for you have given your pledge.' No, by Allah! The hand of the Messenger of Allah (saw) never touched the hand of any woman, rather he accepted their pledge in words only." Aisha said: "By Allah, the Messenger of Allah (saw) did not demand of women (in their pledge) anything other than that which Allah had commanded, and the hand of the Messenger of Allah (saw) never touched the hand of a woman. He would say to them, when he had accepted their pledge: 'You have given your pledge,' verbally."