Musannaf Ibn Abi Shayba 27:627

Abdullah ibn Numayr narrated to us, from al-A’mash, from Uthman Abu al-Yaqzan, from Abu Harb ibn Abi al-Aswad al-Du’ali, who said: I heard Abdullah ibn Amr saying: The earth has not carried, and the sky has not shaded, a man more truthful than Abu Dharr.