Brewer's: Abel and Cain
The Mahometan tradition of the death of Abel is this: Cain was born with a twin sister who was named Aclima, and Abel with a twin sister named Jumella. Adam wished Cain to marry Abel's twin sister, and Abel to marry Cain's. Cain would not consent to this arrangement, and Adam proposed to refer the question to God by means of a sacrifice. God rejected Cain's sacrifice to signify his disapproval of his marriage with Aclima, his twin sister, and Cain slew his brother in a fit of jealousy.