Musnad Abu Ya'la al-Mawsili 6:139

Yahya ibn Ayyub narrated to us, Hassan ibn Ibrahim narrated to us, Yunus ibn Yazid narrated to us, from Muhammad al-Zuhri: Muhammad ibn Abdullah ibn Nawfal informed me that he heard al-Dahhak ibn Qays, during the Hajj of Mu'awiyah ibn Abi Sufyan, saying: "No one gives a legal opinion (fatwa) for the *Tamattu'* (combining) of the 'Umrah with the Hajj except one who is ignorant of the command of Allah." Sa'd ibn Abi Waqqas said to him: "How evil is what you have said, O son of my brother! For by Allah, the Messenger of Allah (may Allah bless him and grant him peace) did that, and we did it with him."