﴿ إِنَّمَا يَفْتَرِى ٱلْكَذِبَ ٱلَّذِينَ لَا يُؤْمِنُونَ بِـَٔايَٰتِ ٱللَّهِ ۖ وَأُو۟لَٰٓئِكَ هُمُ ٱلْكَٰذِبُونَ ﴾

“It is but they who will not believe in God's messages that invent this falsehood; and it is they, they who are lying!”

Only those invent falsehood who do not believe in God’s signs the Qur’an by saying that these are the words of a human and it is they who are the liars the emphasis is effected by way of repetition; wa-inna ‘and indeed’ and other combinations of inna are used in refutation of their saying ‘You are just a fabricator’ above Q. 16101.