Musnad Ahmad 1301:11

Hassan bin Musa and Sulayman bin Harb narrated to us, they said: Hammad bin Salamah narrated to us, from Ali bin Zayd, from Bilal bin Abi al-Darda’, from Abu al-Darda’, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "The sky has not shaded, and the earth has not carried, anyone with a more truthful tongue than Abu Dharr."