Musnad Ahmad 333:5

'Abd al-Rahman ibn Mahdi narrated to us, he said: Ya'la ibn al-Harith narrated to us, he said: I heard Iyas ibn Salamah ibn al-Akwa' narrating from his father, who said: "We used to pray Jumu'ah with the Messenger of Allah, peace and blessings of Allah be upon him, then we would return, and we would not find any shade from the walls to take shelter in."