Surah Ash-Shu'ara, Verse 3

لَعَلَّكَ بَٰخِعٞ نَّفۡسَكَ أَلَّا يَكُونُواْ مُؤۡمِنِينَ٣

laʿallaka bākhiʿun nafsaka allā yakūnū mu'minīna

Perhaps, [O Muḥammad], you would kill yourself with grief that they will not be believers.