If you wish to show that the Jahmī does not affirm Allah’s knowledge, say to him:
Allah says,
‘They do not encompass anything of His knowledge.’ [Q 2:255]
He also says,
‘Yet Allah bears witness to what He has sent down to you; He sent it down with His knowledge.’ [Q 4:166]
And He says,
‘But if they do not respond to you, then know that it was sent down with Allah’s knowledge.’ [Q 11:14]
And He says,
‘No fruit emerges from its sheath, and no female conceives or gives birth, except with His knowledge.’ [Q 41:47]
Then say to him: Do you acknowledge this knowledge of Allah, which He has made plain to you through these signs and proofs, or not? …
• If he says, ‘He has no knowledge,’ he has fallen into disbelief.
• If he says, ‘Allah has a newly-produced knowledge,’ he too disbelieves, for he is claiming that there was a time when Allah did not know until He later brought knowledge into being for Himself and thereby came to know.
• But if he says, ‘Allah has knowledge that is neither created nor originated,’ he has abandoned his entire previous claim and has adopted the creed of Ahl al-Sunnah. ⦗1⦘
He, may Allah have mercy on him, says in Darʾ al-taʿāruḍ: Imam Ahmad has made explicit what sound, self-evident reason already affirms: when the Creator brings the universe into existence, He must either create it separate (mubāyan) from Himself or contiguous (muḥāyith) to Him. If it were contiguous, one of two things would have to follow: either He would be inside the world, or the world would be inside Him. Yet the Exalted subsists by Himself, and anything that subsists by itself—when contiguous to something else—must necessarily indwell the other or be indwelled by it. This differs from what does not subsist by itself, such as attributes, which may all subsist in something else. See also Ibn Taymiyya, Majmūʿ al-Fatāwā, 5/312-313. (1) From his words, may Allah have mercy on him, “when he alleged that He entered into every filthy, repulsive place” until this point, the passage actually belongs to the next section, “An exposition of what Allah stated in the Quran: ‘He is with you.’” This is how it appears in Dr. ʿAmīrah’s edition. I am unsure how it found its way here; perhaps a manuscript page was accidentally placed out of order.