﴿ فَطَوَّعَتْ لَهُۥ نَفْسُهُۥ قَتْلَ أَخِيهِ فَقَتَلَهُۥ فَأَصْبَحَ مِنَ ٱلْخَٰسِرِينَ ﴾

“But the other's passion drove him to slaying his brother; and he slew him: and thus he became one of the lost.”

Then his soul prompted him it seduced him to slay his brother so he slew him and became one of the losers by slaying him. And he did not know what to do with him because he was the first of the Children of Adam to die on earth and so he carried him on his back.