Adam and Eve had two sons. Able and Cain, and one of them killed the other so that he could marry the girl the other wanted to. I want to know from where the girl came? Was she the basis of this murder?
The reason for which Cain killed Abel is mentioned in the Qur’ān in the following words:
Recite to them the story of the two sons of Adam when they offered an offering and it was accepted from one of them and was not accepted from the other. That one said: ‘I will surely kill you’. [The other] replied: ‘The Almighty only accepts the offering of His pious people. (5:27)
In other words, Cain got infuriated when his offering was not accepted by God while that of his brother was accepted by Him. His jealousy ultimately induced him to murder his innocent brother, as is mentioned in 5:30. It is evident from the words of Abel that the reason that Cain’s offering was not accepted by the Almighty was that it was offered by an impious person. This is all what the Qur’ān says.
The Old Testament also mentions this incident. Though it does not explicitly state the reason for the murder yet the context strongly reinforces what the Qur’ān says:
Now Abel kept flocks, and Cain worked the soil. In the course of time Cain brought some of the fruits of the soil as an offering to the Lord. But Abel brought fat portions from some of the firstborn of his flock. The Lord looked with favour on Abel and his offering, but on Cain and his offering he did not look with favour. So Cain was very angry, and his face was downcast.
Then the Lord said to Cain: ‘Why are you angry? Why is your face downcast? If you do what is right will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires you have you; but you must master it.’ Now Cain said to his brother Abel: ‘Let’s go out to the field.’ And while they were in the field Cain attacked his brother Abel and killed him(Genesis, 4:3-8)
Certain historical reports mention another account of the episode. The Jewish Encyclopaedia has summarised the contents of Rabbinical literature on this issue in the following words:
Woman was at the bottom of the strife between the first brothers. Each of the sons of Adam had a twin sister whom he was to marry. As Abel’s twin sister was the more beautiful, Cain wished to have her for his wife and sought to get rid of Abel. (The Jewish Encyclopaedia, 1st ed., vol. 1, [New York: KTAV Publishing House, 1901], p. 48)
It is evident that the above quoted account is in direct contradiction with the Qur’ān and with the Old Testament as well. According to this account, the reason Cain murdered Abel was dispute between the two as regards marriage. On the other hand, both Divine books state Cain got incensed when he saw that his offering had not been accepted by God while that of his brother had been. Consequently, this report cannot be accepted.