Ash-Shura 42:24

Or do they say, “He has fabricated lies about Allah[18]!”? But if Allah willed, He could seal up your heart[19]. Allah wipes out falsehood and establishes the truth by His Words. Indeed, He is All-Knowing of what is in the hearts.

[18] While they are certain of his truthfulness and honesty.
[19] Allah could seal up the whole message by sealing up his heart; then he would not understand anything, so the whole message would then stop if He so willed.

Or do they say, "He has invented about Allāh a lie"? But if Allāh willed, He could seal over your heart.[1422] And Allāh eliminates falsehood and establishes the truth by His words. Indeed, He is Knowing of that within the breasts.

[1422] i.e., He could make you forget the Qur’ān and deprive you of it.

24. Or say they: "He has invented a lie against Allâh?" If Allâh willed, He could have sealed up your heart (so that you forget all that you know of the Qur’ân). And Allâh wipes out falsehood, and establishes the truth (Islâm) by His Word (this Qur’ân). Verily, He knows well what (secrets) are in the breasts (of mankind).

Or say they: He hath invented a lie concerning Allah? If Allah willed, He could have sealed thy heart (against them). And Allah will wipe out the lie and will vindicate the truth by His words. Lo! He is Aware of what is hidden in the breasts (of men).