Musannaf Ibn Abi Shayba 8:1276

Abu Bakr narrated to us, he said: Waki’ narrated to us, from ‘Umar ibn Dharr, from Mujahid; and from Isma’il ibn ‘Abd al-Malik, from ‘Ata’; and from Mis’ar, from Wabarah, from Ibn al-Aswad; and from Sufyan, from a man, from Sa’id ibn Jubayr; they said: The obligatory [prayer] suffices for the two rak’ahs of Tawaf.