According to the text of the Qur’an, Adam and Eve (peace and blessings be upon them all)  were in Heaven (Paradise) when they ate from the forbidden tree. There are many Qur’anic verses stating clearly that they were in Paradise and commanded by Allah to enjoy all blessings in Paradise but not to approach that tree. This was for a Devine wisdom Almighty Allah only knows.

Almighty Allah says, “And (unto man): O Adam! Dwell thou and thy wife in the Garden and eat from whence ye will, but come not nigh this tree lest ye become wrong doers. Then Satan whispered to them that he might manifest unto them that which was hidden from them of their shame, and he said: Your Lord forbade you from this tree only lest ye should become angels or become of the immortals. And he swore unto them (saying): Lo! I am a sincere adviser unto you. Thus did he lead them on with guile. And when they tasted of the tree their shame was manifest to them and they began to hide (by heaping) on themselves some of the leaves of the Garden. And their Lord called them, (saying): Did I not forbid you from that tree and tell you: Lo! Satan is an open enemy to you? They said : Our Lord! We have wronged ourselves. If Thou forgive us not and have not mercy on us, surely we are of the lost! He said: Go down (from hence), one of you a foe unto the other. There will be for you on earth a habitation and provision for a while. He said: There shall ye live, and there shall ye die, and thence shall ye be brought forth.” (Al-A`raf: 19-25)

Having stated the above, it should be stressed that we have to understand such unseen matters in light of the Qur’an and Sunnah. Furthermore, a Muslim should not occupy his mind with such issues upon which work will not result.