Musannaf Ibn Abi Shayba 3:5798

Hussain bin Ali narrated to us, from Za'idah, from Simak, from 'Awn bin Abi Juhayfah, from his father, who said: The Messenger of Allah (ﷺ) led us in prayer in Makkah, the Dhuhr prayer, as two rak'ahs, the prayer of a traveler.