Question 551: When was the first person (Prophet Adam) born? Was the First Children of Adam and Eve Cain (Qabil) and Iqlima or Abel and Layouza?
Answer 551: There is no certain opinion about the number of children of the Prophet Adam (as). Because, there are many differences have been mentioned in authentic historical sources regarding this issue. Since the story of Adam and Eve and their children was for a long time ago the historians were unable to record such information exactly.
According to Tabarsi, when Adam and Eve left Paradise and began their life on earth, Allah (SWT) willed their generation be spread out across the earth. Eve was having twins every time she was giving birth. They named the first twins as follows: the son Cain (Qabil) and the girl Iqlima. Later Eve gave birth to a second set of twins, Abel (Habil) and his sister Layouza.
The children grew up to be reached the age of puberty. In order to maintain and earn livelihood, Cain decided to be a farmer and Abel a rancher.
According to the order coming from Allah the Almighty, Adam told Cain and Abel to present a sacrifice to Allah (SWT). Cain offered a bunch of wheat and Abel presented a sheep as a sacrifice. A fire coming down from the sky took Abel’s sacrifice, but Cain’s sacrifice remained on the earth.
In the Holy Quran Allah (SWT) says: “Relate to them truly the account of Adam’s two sons. When the two of them offered an offering, it was accepted from one of them and not accepted from the other. [One of them] said,” Surely I will kill you.” [The other one] said,” Allah accepts only from the God wary. Even if you extend your hand toward me to kill me, I will not extend my hand toward you to kill you. Indeed I fear Allah, the Lord of all the worlds. I desire that you earn [the burden of] my sin and your sin, to become one of the inmates of the Fire, and such is the requital of the wrongdoers.” So his soul prompted him to kill his brother, and he killed him, and thus became one of the losers. Then Allah sent a crow, exploring in the ground, to show him how to bury the corpse of his brother. He said,” Woe to me! Am I unable to be [even] like this crow and bury my brother’s corpse?” Thus he became regretful.
When Abel was murdered by Cain, Adam (A.S) mourned and lamented on the death of his son… And God, the Almighty granted him Seth (A.S) alone without a twin sister. Seth’s name is Hebatollah [A gift from God] and he is the first man to become the deputy and the successor to a prophet. After Seth (A.S) God granted Adam (A.S) with Japheth without a twin.
In his book Nizam al-Tawarikh, Qadhi Naser Baydawi said about the children of Adam and Eve: Eve gave one hundred and twenty birth. Cain was the fourth body child. According to this opinion, Adam and Eve had 239 children. 
In Tarikh Tabari it is mentioned three opinions about the number of children of Adam and Eve as follows:
- One hundred and twenty Children including girls and boys.
- Forty boys and girls.
- Twenty five boys and 4 girls. 
 . Surah al-Maedah, verses 27-31.
 . Nizam al-Tawarikh, Baydhawi, Naser al-Din, and Mir Hashim, Mohaddith, Pgs. 5-6.
 . Tarikh Tabari, Tarikh al-Umam wal-Muluk, Vol. 1, Pg. 145.
 . Adopted from answer 681.