Musnad Ahmad 1153:2068

Rawh narrated to us, he said: Ibn Abi Dhi’b narrated to us, from Ibn Shihab, from ‘Urwah, from ‘Aishah, she said: We went out with the Messenger of Allah, may Allah bless him and grant him peace, during the Farewell Pilgrimage, and we stopped at al-Shajarah. He said: "Whoever wishes, let him enter into the state of ihram for an ‘Umrah, and whoever wishes, let him enter into the state of ihram for a Hajj." ‘Aishah said: So some of them entered into the state of ihram for an ‘Umrah, and some of them entered into the state of ihram for a Hajj. She said: And I was among those who entered into the state of ihram for an ‘Umrah. Then the day of ‘Arafah overtook me while I was menstruating. The Messenger of Allah, may Allah bless him and grant him peace, said to me: "Undo your hair, comb it, leave your ‘Umrah, and enter into the state of ihram for Hajj." When it was the night of al-Hasbah, he commanded me, so I performed an ‘Umrah in place of the ‘Umrah that I had left.