The writers on religious doctrines have also reported that Jahm used to say that Allah is a thing. This is the meaning of what Ahmad mentioned. For although they described Him as “a thing unlike other things,” they did not mean that He has no equal among them, for that is true. Thus Ahmad did not object to their statement, “There is nothing like Him among all things.” Rather, they intended to deny resemblance in every respect, meaning: “a thing that resembles other things in no respect whatsoever.”
For this reason, Imam Ahmad said: “We said: ‘Rational people recognize that a thing unlike other things is nothing.’ At that point, it became clear to people that they affirm nothing.” Imam Ahmad thus explained that clear reason, shared by all rational people, establishes that whatever resembles other things in no respect whatsoever is nothing—as people have reported Jahm saying. Hence his statement: “At that point, it became clear to people that they affirm nothing”—meaning all rational people. This is not confined to those who follow revelation and Scripture; rather, all rational people share this understanding.
This, then, was a question about His existence. He then questioned them about His being worshipped, for this concerns specifically those who affirm the obligation to worship Allah: the Muslims, past and present.