The Prophet ﷺ said, "No human being is killed unjustly, but a part of responsibility for the crime is laid on the first son of Adam who invented the tradition of killing (murdering) on the earth. (It is said that he was Qabil).
عَنِ النَّبِيِّ ﷺ قَالَ لاَ تُقْتَلُ نَفْسٌ إِلاَّ كَانَ عَلَى ابْنِ آدَمَ الأَوَّلِ كِفْلٌ مِنْهَا