(ז) ויאמר קין אל הבל אחיו ויהי בהיותם וגו'. על מה היו מדיינים? אמרו: בואו ונחלוק את העולם, אחד נטל הקרקעות ואחד נטל את המטלטלין. דין אמר ארעא, דאת קאים עליה דידי! ודין אמר מה דאת לביש, דידי! דין אמר: חלוץ! ודין אמר: פרח! מתוך כך ויקם קין אל הבל אחיו ויהרגהו. רבי יהושע דסכנין בשם רבי לוי אמר: שניהם נטלו את הקרקעות, ושניהן נטלו את המטלטלין. ועל מה היו מדיינין? אלא, זה אומר: בתחומי בהמ"ק נבנה. וזה אומר: בתחומי בהמ"ק נבנה, שנא' ויהי בהיותם בשדה, ואין שדה אלא בהמ"ק. היך מה דאת אמר (מיכה ג): ציון שדה תחרש. ומתוך כך (בראשית ד): ויקם קין אל הבל אחיו וגו'. יהודה בר אמי אמר: על חוה הראשונה היו מדיינין. אמר רבי איבו: חוה הראשונה חזרה לעפרה. ועל מה היו מדיינין? אמר רבי הונא: תאומה יתירה נולדה עם הבל. זה אומר: אני נוטלה, שאני בכור. וזה אומר: אני נוטלה, שנולדה עמי.
(7) ..."And Cain spoke to Abel his brother. And it came to pass when they were in the field... " (Gen 4:8) What were they fighting about? They said, "Let's divide up the world." One took the earth and one took the moveable objects. One said "That land that you are standing on is mine!" and the other said "What you are wearing is mine!" One said "Take it off!" and the other said "Fly!" Because of this, "Cain rose up against Abel his brother and slew him. Rabbi Joshua of Sikhnin in the name of Rabbi Levi said: they each took earth and each took moveable objects. And what were they fighting about? One said, "The Temple will be built in my territory!" and the other said "The Temple will be built in my territory!" as it is written "when they were in the field"-- and "field" can refer only to the Temple, hence what is written: "Zion shall be threshed as a field" (Micah 3). And because of this, "Cain rose up against Abel his brother." Judah bar Ami said: they were fighting about Primordial Eve. Rabbi Eivo said: Primordial Eve had already died. And what were they fighting about? Rabbi Huna said: A twin girl was born along with Abel. One said, "I will take her, because I am the firstborn." And the other said, "I will take her because she was born with me."
Midrash Tanhuma
What Cain said to Abel was, "Come and let us divide the world between us." Abel replied, "very well." So Cain said, You take the flocks and I will take the land." And it was agreed between them that the division was final and neither could take what belonged to the other..
Nevertheless, when Abel proceeded to graze the flock, Cain replied, "the land you are grazing on is mine!" Abel replied, "the wool you are wearing is mine!" Cain proceeded to chase Abel until the two grappled. Abel overcame Cain, so that Cain fell underneath him. Cain, aware of how badly it was going for him, began to plead aloud: Abel, my brother, there are only two of us in the world...what are you going to tell our father?
Abel, filled with compassion for his brother, let him go. At once Cain rose up against him and slew him. How did he slay him? Cain took a stone and inflicted many contusions and bruises on Abel's arms and legs, for he did not know what part of the body the soul goes out of, until, when he got to Abel's neck, Abel died.