﴿ إِنَّ ٱلَّذِينَ كَفَرُوا۟ سَوَآءٌ عَلَيْهِمْ ءَأَنذَرْتَهُمْ أَمْ لَمْ تُنذِرْهُمْ لَا يُؤْمِنُونَ ﴾

“BEHOLD, as for those who are bent on denying the truth - it is all one to them whether thou warnest them or dost not warn them: they will not believe.”

As for the disbelievers the likes of Abū Jahl Abū Lahab and such; alike it is for them whether you have warned them or have not warned them they do not believe as God knows very well so do not hope that they will believe read a-andhartahum pronouncing both hamzas or by not pronouncing the second making it an alif instead and inserting an alif between the one not pronounced and the other one or leaving this insertion; al-indhār ‘warning’ is to give knowledge of something and simultaneously instil an element of fear.