﴿ 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 they invent falsehood) about Allah those (who believe not Allah's revelations) i.e. Muhammad (pbuh) and the Qur'an, (and (only) they are the liars) about Allah.