"Lest you destroy yourself [with grief]," meaning: you are killing yourself if they do not believe in this Qur'an; that is: do not do that.
﴿لَعَلَّك باخع نَفسك﴾ أَيْ: قَاتِلٌ نَفْسَكَ إِنْ لَمْ يُؤْمِنُوا بِهَذَا الْقُرْآنَ؛ أَيْ: فَلَا تفعل
