It is reported that Al-Fudayl b. ʿAyyāḍ said, “When backbiting appears, brotherhood for Allāh will disappear; and at that time you will be like things plated with gold and silver: wooden on the inside, [merely] looking good on the outside.”

Abū Nu’aym, Hilyah Al-Awliyā', Vol. 3 p395.