Jahmiyyah: They ascribe themselves to Jahm Ibn Safwaan as-Samarqandee. And he is the one who manifested negation of the Attributes, ta’teel (denial) and other than that from the abaateel (false understandings). Indeed, he took that from al-Ja’d Ibn Dirham, and he was the one who took that chain of understanding from a filthy Jew.

Indeed, Ja’d Ibn Dirham was killed by Khaalid al-Qasree in the year 124H, in Waasit. So Jahm succeeded him in Khuraasaan. So he manifested his statements there, and the people followed him upon that. After that, he abandoned the Prayer for forty days because he doubted in his Lord. Indeed, Jahm was killed in Khuraasaan. He was killed by Salim Ibn Ahwaz al-Maazinee, during the end of the rule of Banee Umayyah. However, his statements had flourished amongst the people. So these statements did not cease to remain strong amongst the people and multiply, not to mention during the time of al-Ma‘moon.

And from the fabrications of Jahm and his followers are that Paradise and the Fire shall pass away, that eemaan is ma’rifah (knowledge) only, that kufr is jahl (ignorance) only, that no one performs an action in truth besides Allaah alone, that the actions of the people can only be attributed to them metaphorically, that the knowledge that Allaah possesses has newly come about and other than that from the abaateel (false views) whose misguidance and heresy is not hidden. And along with his misguidances that we have mentioned, Jahm used to carry a weapon and fight the ruler. Indeed, how beautiful is the statement of the poet,

‘I am amazed at a Shaytaan who calls the people openly;
to the Fire. And his name has been derived from: Jahannam.’

Refer to Sharhul-’Aqeedatit-Tahaawiyyah (p. 522-524), al-Milal wan-Nihal (1/86-88) of ash-Shahrastaanee and al-Farq baynal-Firaq (p. 128) of al-Baghdaadee.

Source: Ibn Taymiyyah On Trial: A Complete Undoing of Recycled Jahmee Rhetoric, Sunnah Publishing, Translation by Maaz Qureshi.