فَإِن لَّمۡ يَسۡتَجِيبُواْ لَكَ فَٱعۡلَمۡ أَنَّمَا يَتَّبِعُونَ أَهۡوَآءَهُمۡۚ وَمَنۡ أَضَلُّ مِمَّنِ ٱتَّبَعَ هَوَىٰهُ بِغَيۡرِ هُدٗى مِّنَ ٱللَّهِۚ إِنَّ ٱللَّهَ لَا يَهۡدِي ٱلۡقَوۡمَ ٱلظَّٰلِمِينَ ٥٠
But if they do not respond to you - then know that they only follow their [own] desires. And who is more astray than one who follows his desire without guidance from Allāh? Indeed, Allāh does not guide the wrongdoing people.
Translation: Saheeh International (English)
Each word's meaning and sound
And if they do not take up your challenge to bring a book better guiding than the Torah and Qur’ān, know for certain that their rejection of the two is not based on any proof; it is only a result of following their own desires. There is no one more deviant than the one who follows his desires without guidance from Allah, may He be glorified. Allah does not grant a nation who wrongs itself through disbelief in Allah, opposing His Messengers and countering the truth that comes to them from Allah with falsehood, the ability to be guided.
Al-Mukhtasar in interpreting the Noble Quran