knowledge they possessed, and they were engulfed by what they used to mock. * Then, when they saw Our punishment, they said, ‘We believe in Allah alone and reject what we used to associate with Him.’ * But their faith could not benefit them once they had seen Our punishment. Such is Allah’s established way with His servants, and there the unbelievers lost everything.”
[Ghāfir: 83–85]

And He says:

“Those who dispute Allah’s signs without any authority having come to them are greatly detested by Allah and by those who believe.”
[Ghāfir: 35]

And in the other verse:

“There is nothing in their hearts but pride whose goal they will never attain. So seek refuge in Allah. Indeed, He is the All-Hearing, the All-Seeing.”
[Ghāfir: 56]

“Authority” means proof revealed by Allah, as Allah Most High says:

“Or have We sent down to them an authority that speaks in support of what they associate with Him?”
[al-Rūm: 35]

And Allah Most High says:

“Or do you have clear authority? * Then bring your scripture, if you are truthful.”
[al-Sāffāt: 165–157]

And He says:

“They are nothing but names you and your forefathers have given them, for which Allah has sent down no authority.”
[al-Najm: 23]

Allah Most High has demanded evidence from anyone who adopts a religion, saying:

“Bring me a scripture preceding this, or a remnant of knowledge, if you are truthful.”
[al-Ahqāf: 4]

Here, “a book” means a scripture, while ithāra (a remnant of knowledge), as some of the early generations explained, means transmitted reports and their chains of transmission,