Girl with a pomegranate – William-Adolphe Bouguereau (1825–1905)
A popular misconception is that the “forbidden fruit” was an apple, neither the Qur’an or the Bible substantiate this claim. As for what the fruit was, no one really knows but some popular candidates proposed by scholars are the pomegranate, fig, grape, citron, and even wheat. Ironically the latter, which isn’t even a fruit, may well have the strongest claim.
Why wheat? Eating the “forbidden fruit” was connected with a harder life, full of toil and tilling the ground. Learning to cultivate wheat was a crucial turning point in Human history, associated with a life of hard work, ploughing the ground, looking after crops, digging and maintaining irrigation channels etc.
Even after grain is harvested, it needs to be cleaned, preserved, ground into flour before finally being baked into bread, made into pasta etc. This involved a lot more work than picking fruit from a tree and requires a lot more knowledge, another feature associated with the forbidden fruit.
Whatever the fruit was, it’s impact on society, religion and culture remains with us. What do you think it was and why?
Paul Salahuddin Armstrong 
The olive tree, God clearly warns the Jews not to cut them down
Wheat brought about civilization. Civilization defines what good and evil is. Wheat brought about the luxury of extra time to relax after the harvest. Time to relax and to wonder and question the metaphysical. Time to get into mischief and piss others off. Laws were made to make peace. Not everyone agreed on the laws, war ensued. A hunter gatherer has no time for these luxuries of war, politics, and philosophy. He must focus on his next meal and protecting his tribe etc. A pre-wheat society lived amongst the forests, plains etc. In the garden, gods garden. A man can have the heart of a lion or be meek like the lamb. They lived and lay together for survival. The lion lay with the lamb.
Could the identity of the unknown forbidden fruit in the world’s oldest and greatest mystery story have something to do with procreation and the family Adam and Eve do not have until after their eviction from Eden at the end of Genesis 3? Adam and Eve disobey the Genesis 1:28 commandment–the first commandment–to “be fruitful and multiply [in the Garden]” when they become one flesh incorrectly (Genesis 2:24) by eating from the wrong tree in the allegorical Garden’s center (Genesis 2:9). So they disobey not just one commandment, but two at the same time. Finally, it is interesting that half of Eve’s punishment in Genesis 3:16 is painful childbirth–because she chooses to not have children in the Garden of Eden and God wants to remind her of her decision?
The entire evidence-based exegesis is included in the preceding four sentences. But why was this confusing allegory, whatever its meaning, constructed in the first place, as the original literal story most certainly came first, a story that confused absolutely no one, unlike the allegory into which it evolved? The widely held belief that the forbidden fruit in the Bible story is an apple illustrates among other things how confirmation bias serves as a terrible mechanism that cripples our critical thinking as it prevents discussion, criticism, and evaluation of the validity of the proposed exegesis that begins with Genesis 1:28, continues through Genesis 2 and 3, and concludes with Genesis 4:1. So the struggle continues in an effort to protect the self-esteem of so many who have held lifelong beliefs they are unable to change.