That made Kayin extremely jealous!
"Kayin," said HaShem. "Why are you angry and sad? It's true that this time your sacrifice was not accepted, but you can surely do better next time! If you try to improve, I will forgive you."
But Kayin didn't want to hear about it. He went to his brother and said, "Hey, Hevel! It's not fair! HaShem accepted your sacrifice, but he rejected mine!"
Kayin worked himself up into such a rage that he picked up a heavy rock and started to hit Hevel with it. He kept smacking his brother with the rock until, finally, with one last blow to his neck, he killed him!
Soon after that, HaShem said to Kayin, "Where is your brother, Hevel?"
Kayin replied, "I don't know. Am I my brother's keeper?"
HaShem said, "What have you done? Not only did you kill your brother, but also all of his future descendants!"
Think about it... when Kayin killed Hevel, he killed a large percentage of the entire world's population at that time (since there were just a few people on earth - plus billions of people that would have come from him in future generations).
"Kayin," said HaShem, "you know that I know everything, and I will punish you for what you did. From now on, the ground will be even more cursed because of you! When you work the land, you will only harvest a little bit for all of your efforts. And from this day on, you will be a wanderer, without a home."
"Oh, HaShem! I did a terrible thing! And now I'm afraid that when I travel from place to place, wild animals will kill me."
"You must repent and change your ways for the good! If you do this, and if your children and your children's children remain good for seven generations, then I will not destroy you. Also, in the meantime, to protect you from being harmed by animals, I will mark your forehead with a letter of My holy name."
Kayin headed east, and settled for a while in the land of Nod.
In next week's parsha, generations have passed... and things are getting worse. People aren't behaving nicely at all! But there is one good man, named Noach...
