Musnad Ahmad 1153:1748

Waki' narrated to us, al-A'mash narrated to us, from Habib ibn Abi Thabit, from 'Urwah ibn al-Zubayr, from 'Aishah, that the Messenger of Allah (peace and blessings of Allah be upon him) kissed some of his wives, then went out to the prayer, and did not perform ablution. 'Urwah said: I said to her, "Who is she, if not you?" He said: So she laughed.