Musnad Ahmad 985:2

'Affan narrated to us, Hammad bin Salamah narrated to us, Ya'la bin 'Ata' informed us, from 'Abdullah bin Yasar Abu Hammam, from Abu 'Abd al-Rahman al-Fihri, who said: I was with the Messenger of Allah, may Allah bless him and grant him peace, during the Battle of Hunayn, and we traveled on a scorching hot day. He then mentioned the like of it.