Abū Sa‘īd said: “One day I began recounting the statements of the Jahmiyyah to Yahyā ibn Yahyā, hoping to elicit from him a refutation of them. Present at his gathering that day were al-Husayn ibn ‘Īsā al-Bistāmī, Ahmad ibn Harīsh the judge, Muhammad ibn Rāfi‘, Abū Qudāmah al-Sarakhsī—as I recall—and other scholars. He rebuked me angrily and said, ‘Be silent!’ The scholars present also reproached me, appalled that I should recount the statements of the Jahmiyyah and condemning them.

What, then, of someone who recounts their statements as a matter of religious belief! Then Yahyā said: ‘The Quran is the speech of Allah. Whoever doubts this or claims that it is created is an unbeliever.’”

[Commentary by Ibn Taymiyyah]

I say:

The statements of the early generations and the imams declaring the Jahmiyyah to be unbelievers, and explaining that their doctrine entails the negation of Allah’s attributes and heresy, are numerous. This is not the place to set them out in detail.

‘Abd Allāh ibn al-Mubārak and Yūsuf ibn Asbāt were asked about this and gave the answers mentioned above.

It has become clear that, in their view, the Jahmiyyah belong to the kind of heretics whose doctrine is self-evidently contrary to what the messengers brought. Indeed, denying Allah’s attributes is a graver form of heresy in the religion of the messengers than denying bodily resurrection, for the messengers’ teachings affirming Allah’s attributes are greater than their teachings concerning bodily resurrection.