What happened on the fields to Kain and Hevel?

Now the man knew his wife Eve, and she conceived and bore Cain, and she said, "I have acquired a man with the Lord. And she continued to bear his brother Abel, and Abel was a shepherd of flocks, and Cain was a tiller of the soil. Now it came to pass at the end of days, that Cain brought of the fruit of the soil an offering to the Lord. And Abel he too brought of the firstborn of his flocks and of their fattest, and the Lord turned to Abel and to his offering. But to Cain and to his offering He did not turn, and it annoyed Cain exceedingly, and his countenance fell. And the Lord said to Cain, "Why are you annoyed, and why has your countenance fallen? Is it not so that if you improve, it will be forgiven you? If you do not improve, however, at the entrance, sin is lying, and to you is its longing, but you can rule over it." And Cain spoke to Abel his brother, and it came to pass when they were in the field, that Cain rose up against Abel his brother and slew him. And the Lord said to Cain, "Where is Abel your brother?" And he said, "I do not know. Am I my brother's keeper?" And He said, "What have you done? Hark! Your brother's blood cries out to Me from the earth. And now, you are cursed even more than the ground, which opened its mouth to take your brother's blood from your hand. When you till the soil, it will not continue to give its strength to you; you shall be a wanderer and an exile in the land." And Cain said to the Lord, "Is my iniquity too great to bear? Behold You have driven me today off the face of the earth, and I shall be hidden from before You, and I will be a wanderer and an exile in the land, and it will be that whoever finds me will kill me." And the Lord said to him, "Therefore, whoever kills Cain, vengeance will be wrought upon him sevenfold," and the Lord placed a mark on Cain that no one who find him slay him. And Cain went forth from before the Lord, and he dwelt in the land of the wanderers, to the east of Eden. (Bereshit 4, 1-16)

Rav Sharki gives the following interpretation to the fourth chapter (the commentary is based mainly on pshat, almost the literal meaning of the words, and a bit of a Midrash):

According to the Jewish tradition Adam had marital relations with Chava before they were expelled from the Paradise. We learn this from the first verse: "Ve-ha-Adam yada et Chava ishto" (instead of Va-yeda ha-Adam, see Rashi there).
When Hevel was born, Kain understood that he is no more THE son, but he has from now a competitor. Thus, already at the birth of Hevel, the murder was anticipated. Kain was born egoist, into the reality, where there is no competition. Hevel was born into the reality, where he understood, that he has to share - therefore he will give the best to the other, and the rest will keep, unlike Kain.
Kain says: I am egoist by nature. What do you want from me, Hashem? This is my nature and I cannot change. But Hashem interrogates and challenges, and reveals a novelty:
Kain, you have, as a human being, a free will. You can choose how you will be, how you will act and react. And therefore, being born as an egoist is actually an advantage, because you can choose to be good (while your initial parameters were negative), and it will be understood as a greater achievement than being born good and righteous. The free choice is a reaction on our initial parameters, not their function.
Hashem says to Kain: If you want/choose to succeed, you will win (Im tetiv, set.). But if you do not use the power of free choice, the sin is there waiting for you. But even there, you have the power to overcome it.
What was Kain's reaction? 'And Kain said to Hevel, his brother.' Until now, he didn't call Hevel his brother. Now, when Hashem told him he can revert his 'fate', he comes to Hevel and says: You are my brother, lets live in peace. But what happened afterwards? They tried to speak, but it did not succeed, and the story ended by death. Fields is the space of nature, of competition - that is a hint to the subject to their conversation. Whatever it was, they quarreled (opinions are many: they argued about the crops and the cattle, about a woman, or holy sites; there is also opinion that they talked about something, that was not even considered conversation, and that is why the Torah doesn't note it). This teaches us, that we know from the beginning, what are the source of quarrels, wars and murder. Nevertheless, our free choice stands above them all, because human morality is more than human animal nature (if we choose so). [As I understand it, when we wonder why people are bad and why they sin, why they hurt other people, and are immoral, I do not wonder about the fact they do these things, but rather about the fact they choose to do them, despite they can choose to act rightly. This is not a mere detail in understanding, but a huge difference - between naivity and morality.]
Kain chose not to use his free will for good, and murdered his brother. His punishment was to wander in the world - a fate that is completely against his sedentary nature (agriculturist). Because the soil, his occupation was the source of the sin, it was necessary to disconnect him from the soil to correct his path. In the end, he really undergoes some amendment.
What was the sin of Hevel? Why did he die? It is written: 'And Kain stood up towards Hevel, his brother, and killed him.' (4, 8). It means, that he lied on the ground - Hevel knocked him down. But he did not used his advantage to kill Kain first. He didn't understand, that had he killed Kain, he would not been called murderer, as the justice was on his side (he only defended himself). It follows, that Hevel did a fatal mistake by not killing, when he should have done that in order to save his own life. That is the hidden sin of Hevel, which is only hinted in the Torah. After that, Shet was born - a better version of Hevel. A person, whom Kain cannot kill, because he defends himself, but at the same time he doesn't become like Kain.
What a surprise then, when Kain blames Hashem for the murder: 'Am I my brother's keeper?' He says actually: Hashem, you were his keeper, and you still let me to kill him. Why do you then rebuke me? I used the possibility of free choice, which was what you wanted me to do. Hashem answers: 'What did you do?' You didn't kill Hevel because you wanted to fulfill my will (leshem Shamayim), but rather for low reasons. And therefore it counts as a sin.


The big lesson of this story is simple, and argues for example with the Greek mythology, based on determining parameters and an inevitable human disaster. The Torah acknowledges human nature, its flaws and negative potentials, but it teaches us, that it is not only a possibility, but also a moral command, to surpass this nature and live in congruence with the given moral.