Musnad Abu Ya'la al-Mawsili 193:1

'Abd al-A'la ibn Hammad al-Narsi narrated to us, Wahib narrated to us, 'Amr ibn Yahya narrated to us, from Abu Zayd, from Ma'qil ibn Abi Ma'qil al-Asadi, who said: It was said, "O Messenger of Allah, indeed Umm Ma'qil became sad when the Hajj with you escaped her." He said, "Then let her perform 'Umrah in Ramadan, for an 'Umrah in Ramadan is like a Hajj."