Musnad Ahmad

Mujahid (may Allah have mercy on him) says that once I and Urwah bin Zubair (may Allah have mercy on him) entered the mosque. We reached Syedna Ibn Umar (may Allah be pleased with them both) and sat with him. There were some people performing the Duha prayer there. We asked him, "O Abu Abdur Rahman, what kind of prayer is this?" He replied, "It is an innovation." We asked him, "How many Umrahs did the Prophet (peace and blessings be upon him) perform?" He replied, "Four, one of which was in Rajab." We felt shy to refute his statement, but at that very moment, we heard the sound of the Mother of the Believers, Syeda Aisha (may Allah be pleased with her) using the miswak. So Urwah bin Zubair (may Allah have mercy on him) said to her, "O Mother of the Believers, did you hear what Abu Abdur Rahman is saying? He is saying that the Prophet (peace and blessings be upon him) performed four Umrahs, one of which was in Rajab." She replied, "May Allah have mercy on Abu Abdur Rahman. The Prophet (peace and blessings be upon him) performed every Umrah with him present, and the Prophet (peace and blessings be upon him) did not perform any Umrah in Rajab."