The sons of Adam and the first act of murder 5:27-31
5:27 Recite to them in all truth the news of Adam's two sons; how they each made an offering, and how the offering of the one was accepted while that of the other was not. He said, 'I will surely kill you.' (The other) said, 'Allah accepts only from the righteous.
5:31 Then Allah sent down a crow, which dug the earth to show him how to bury the naked corpse of his brother. 'Alas!' he said, 'am I unable to be like this crow and so I bury my brother's naked corpse.' And he became among those who regret.