Musnad Ahmad 937:241

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Humayd ibn Hilal, from Abdullah ibn al-Samit, from Abu Dharr, from the Prophet, may Allah bless him and grant him peace, that he said: "Verily, there will be people from my nation whose mark is shaving [the head]. They recite the Quran, but it does not pass beyond their throats. They pass through the religion just as an arrow passes through the game. They are the worst of the creation and the creatures."