Surah 5:30
"Then his (own) self compelled him to the killing of his brother. So he killed him and became one of the losers."
5.30 – Then his (own) self compelled him to the killing of his brother.
This verse says that the self or soul (nafs) of Cain prompted or “compelled” him to kill his brother Abel. This expression fits into a series of verses that hint at a deeper diagnosis of human nature. See the analysis of this idea at 79.40.
- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam