Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
Bukhari :: Book 6 :: Volume 60 :: Hadith 169
Narrated Ibn 'Abbas:
Regarding the Verse: "Verily! The worst of beasts in the Sight of Allah are the deaf and the dumb----those who understand not." (8.22)
(The people referred to here) were some persons from the tribe of Bani 'Abd-Addar.