In Parshat Breisheet 4:8 we encounter a perplexing account: "Kayin said to his brother Hevel. It happened when they were in the field (sadeh), that Kayin rose up against his brother Hevel and killed him."

The pasuk never tells us what their conversation was about.

Breisheet Raba 22:7 gives us insight into three different possibilities as to what Kayin and Hevel may have been arguing about:

1. Materialism: The pasuk mentions that they were in the field so their conversation must have had something to do with a field or land. They said: "Lets divide up the world." Kayin said, "You take the moveable property and I will take the immovable property (This makes sense since Hevel was a shepherd and Kayin worked the land). Kayin said, "The land that you are standing on is mine, go fly away." Hevel said, "The clothing that you are wearing is mine." Kayin tried to chase Hevel off of his property and ultimately killed him.

2. Religion: According to Rabbi Yehoshua of Sachnin who quotes Rabbi Levi, they were fighting concerning the sadeh, field, which is traditionally how the Beit Hamikdash was referred to. One said "On my land the Beit Hamikdash will be built" and the other said "On my land the Beit HaMikdash will be built. Their argument continued until Kayin finally killed Hevel.

3.Women: a person is referred to in the chumash as a field (Dvarim 20:19: Ki HaAdam etz Hasadeh). According to Yehudah Bar Ami they were fighting over Chava. Rabbi Ivo points out that Chava was no longer alive so they couldn't have been fighting over her. Rabbi Huna's opinion is that Hevel was born with a twin sister which they both wanted to marry. Their fight over a woman caused Kayin to kill Hevel.

All we have to do today is open up the newspaper and find that unfortunately we have still not learned our lesson. Most murders are still committed for the same reasons that we find in Breisheet Raba: materialism, religion and male-female relationships.