(1b) CHAPTER. Verily! The worst of (moving) living creatures with Allah are the deaf and the dumb, those who understand not (i.e., the disbelievers). (V.8:22)
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.