Quran 5:30 — The Feast (Al-Ma'edah)

His ego provoked him into killing his brother. He killed him, and ended up with the losers.

[5:29] "I want you, not me, to bear my sin and your sin, then you end up with the dwellers of Hell. Such is the requital for the transgressors."

[5:31] GOD then sent a raven to scratch the soil, to teach him how to bury his brother's corpse. He said, "Woe to me; I failed to be as intelligent as this raven, and bury my brother's corpse." He became ridden with remorse.