Cain said to his brother Abel … and when they were in the field, Cain set upon his brother Abel and killed him.

“Cain said to Abel his brother. It was when they were in the field. Cain rose up against Abel his brother and killed him” (Genesis 4:8). “Cain said to Abel his brother. It was when they were…” – about what were they quarreling? They said: ‘Let us divide the world between us.’ One took the land and one took the movable property. This one said: ‘The land on which you are standing is mine.’ That one said: ‘What you are wearing is mine.’ That one said: ‘Take it off.’ This one said: ‘Fly.’ As a result: “Cain rose up against Abel his brother and killed him.” Rabbi Yehoshua of Sikhnin said in the name of Rabbi Levi: Both of them took the land and both of them took the movable property. Regarding what, then, were they quarreling? Rather, this one said: ‘The Temple shall be built in my domain,’ and that one said: ‘The Temple shall be built in my domain,’ as it is stated: “It was when they were in the field,” and “field” is nothing other than the Temple, as it says: “Zion will be plowed like a field” (Micah 3:12). As a result: “Cain rose up against Abel his brother…” Yehuda bar Rabbi said: They were quarreling over [who would wed] the first Eve. Rabbi Aivu said: The first Eve had returned to dust. Regarding what, then, were they quarreling? Rabbi Huna said: An extra twin sister was born with Abel. This one [Cain] said: ‘I will take her, as I am the firstborn.’ That one [Abel] said: ‘I will take her, as she was born with me.’ As a result: “Cain rose up.”