Musnad Ahmad 1153:1892

Muhammad ibn Salamah narrated to us, from Ibn Ishaq, from Yahya ibn 'Abbad, from his father 'Abbad ibn 'Abdullah ibn al-Zubayr, who said: I entered upon 'Aishah, and she said: "The Messenger of Allah (peace and blessings of Allah be upon him) did not perform 'Umrah except in Dhu al-Qa'dah, and he performed three 'Umrahs."