They are the followers of Jahm Ibn Safwān (executed 128H), the negator! Imaam Ahmad Ibn Hanbal (d. 241) said: “The Jahmiyyah are the enemies of Allāh. They are the ones who claim that the Qur’an is created; that Allah did not speak to Moosā (‘alaihis-salām) and that Allāh is not a speaker nor one who speaks, and He cannot talk – and there is much that can be said and I hate even to narrate it. And they are unbelievers, heretics, enemies of Allāh.”
See Tabaqātul-Hanābilah, 1/32.