[The words of ʿAbd al-Raḥmān ibn Mahdī]:
It is reported from the renowned Imām ʿAbd al-Raḥmān ibn Mahdī that he said, “Among all the sectarian deviants, none are worse than the followers of Jahm. Everything they say ultimately revolves around the claim, ‘There is nothing in the heaven.’ By Allah, I hold that they should neither intermarry with Muslims nor be entitled to inheritance.”

ʿAbd al-Raḥmān ibn Abī Ḥātim also relates in his book The Refutation of the Jahmiyyah that ʿAbd al-Raḥmān ibn Mahdī said, “The adherents of Jahm want to say that Allah did not speak to Moses; they want to say, ‘There is nothing in the heaven,’ and that Allah—”