Quran 5:30

فَطَوَّعَتْ لَهُۥ نَفْسُهُۥ قَتْلَ أَخِيهِ فَقَتَلَهُۥ فَأَصْبَحَ مِنَ ٱلْخَٰسِرِينَ

And his soul permitted to him the murder of his brother, so he killed him and became among the losers.

Translation · Saheeh International