18:6
فَ لَعَلَّ كَ بَٰخِعٌ نَّفْسَ كَ عَلَىٰٓ ءَاثَٰرِ هِمْ إِن لَّمْ يُؤْمِنُ وا۟ بِ هَٰذَا ٱلْ حَدِيثِ أَسَفًا
Then perhaps you would kill yourself through grief over them, [O Muhammad], if they do not believe in this message, [and] out of sorrow.
26:3
لَعَلَّ كَ بَٰخِعٌ نَّفْسَ كَ أَ لَّا يَكُونُ وا۟ مُؤْمِنِينَ
Perhaps, [O Muhammad], you would kill yourself with grief that they will not be believers.