And those who disbelieve say, "This [Qur'an] is not except a falsehood (25:4)

﴿وَقَالَ الَّذِينَ كَفَرُوا إِنْ هَٰذَا إِلَّا إِفْكٌ افْتَرَاهُ وَأَعَانَهُ عَلَيْهِ قَوْمٌ آخَرُونَ ۖ فَقَدْ جَاءُوا ظُلْمًا وَزُورًا﴾
[ الفرقان: 4]

25:4 And those who disbelieve say, "This [Qur'an] is not except a falsehood he invented, and another people assisted him in it." But they have committed an injustice and a lie.

And those who disbelieved in Allah and His Messenger said: “This Qur’ān is nothing but a lie which Muhammad has fabricated and blasphemously attributed to Allah.
Other people have also helped him in its fabrication”.
These disbelievers themselves have made a false statement, because the Qur’ān is the speech of Allah; it is impossible for humans and jinn to come up anything like it.

Those who disbelieve say: "This (the Quran) is nothing but a lie that he (Muhammad SAW) has invented, and others have helped him at it, so that they have produced an unjust wrong (thing) and a lie."

phonetic Transliteration

Waqala allatheena kafaroo in hatha illa ifkun iftarahu waaAAanahu AAalayhi qawmun akharoona faqad jaoo thulman wazooran

Abdullah Yusuf Ali - Translation

But the misbelievers say: "Naught is this but a lie which he has forged, and others have helped him at it." In truth it is they who have put forward an iniquity and a falsehood.

Safi-ur-Rahman al-Mubarakpuri

Those who disbelieve say: "This is nothing but a lie that he has invented, and others have helped him in it." In fact, they have produced an unjust wrong and a lie.

Page 360 English transliteration