These men—as Abū Hāmid noted—fall into this category. The early generations’ condemnation of speculative theological discourse encompasses what Allah has condemned in His Book. Allah, glorified be He, has condemned both false speech and speaking without knowledge.

The former is condemned in many passages. As for the latter, He, Most High, says:

“Say, ‘My Lord has only forbidden indecencies, whether open or hidden, sin, unjust aggression, associating with Allah that for which He has sent down no authority, and saying about Allah what you do not know.’”
[al-A'rāf: 33]

He, Most High, also says:

“Here you are, having argued about what you have knowledge of. Why, then, do you argue about what you have no knowledge of?”
[Āl 'Imrān: 66]

And He says:

“Do not pursue that of which you have no knowledge. Indeed, the hearing, the sight, and the heart—each of these will be questioned.”
[al-Isrā': 36]

Both kinds of speech are blameworthy in judicial rulings, the issuing of fatwas, and Quranic interpretation. The Prophet, may Allah bless him and grant him peace, said:

“Judges are of three kinds: one is in Paradise, and two are in the Fire. A man who knows the truth and judges accordingly is in Paradise; a man who judges between people in ignorance is in the Fire; and a man who knows the truth but rules contrary to it is in the Fire.”