Musannaf Ibn Abi Shayba 27:629

Yazid narrated to us, from Abu Umayyah bin Ya'la al-Thaqafi, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (ﷺ) said: "The sky has not shaded, and the earth has not carried, anyone with a tongue more truthful than Abu Dharr. Whoever is pleased to look at the humility of 'Isa bin Maryam, let him look at Abu Dharr."