18:6
فَلَعَلَّكَ بَـٰخِعٌ نَّفْسَكَ عَلَىٰٓ ءَاثَـٰرِهِمْ إِن لَّمْ يُؤْمِنُوا۟ بِهَـٰذَا ٱلْحَدِيثِ أَسَفًا
falaʿallaka bākhiʿun nafsaka ʿalā āthārihim in lam yu'minū bihādhā l-ḥadīthi asafan
But [Prophet] are you going to worry yourself to death over them if they do not believe in this message?
Perhaps, you, would kill yourself (O Muhammad صلى الله عليه وسلم) in grief, over their footsteps (for their turning away from you), because they believe not in this narration (the Qur’ân).