(1) Now the man knew his wife Eve, and she conceived and bore Cain, saying, "I have gained a male child with the help of the LORD." (2) She then bore his brother Abel.
Adam was not in the company of Eve during the time of her pregnancy with Cain.
ותוסף ללדת את אחיו את הבל, the construction of ותוסף ללדת instead of ותהר עוד ותלד, "she again became pregnant and gave birth," supports the words of our sages in Bereshit Rabbah 22,2 that the two brothers Kayin and Hevel were born as twins. The birth was additional, not the pregnancy.
Abel became a keeper of sheep, and Cain became a tiller of the soil.
ויהי הבל רועה צאן, as the brothers grew up, they divided their occupation in accordance with their respective needs. The one who became the shepherd was interested in eating the dairy products obtainable from the sheep and goats. He was also in need of the wool of the sheep to make clothing. They restricted themselves to these vocations, seeing that G-d had not permitted the eating of meat but only grass, fruit of the trees, and bread after backbreaking labour. The generations until the deluge adapted themselves to this lifestyle. It was only in Genesis 9:3 that G-d permitted killing animals for the purpose of eating their meat.
רעה צאן A FEEDER OF FLOCKS — Because the earth had been cursed [Abel] refrained from cultivating it.
(3) In the course of time, Cain brought an offering to the LORD from the fruit of the soil; (4) and Abel, for his part, brought the choicest of the firstlings of his flock. The LORD paid heed to Abel and his offering, (5) but to Cain and his offering He paid no heed. Cain was much distressed and his face fell.
וקין היה עובד אדמה, as a result of each having his own vocation, they each brought different offerings to G’d.
ויבא קין מפרי האדמה, "Kayin brought an offering to G-d from the fruit of the earth;" according to Rashi, he had chosen the most inferior of the fruit of the earth. He refers to a Midrash which says that it was flax seed.
The reason why G-d rejected his offering was that he offered something which 1) was of no use to him as he had plenty of it; 2) that it was the product of the earth which G-d had cursed.
His brother Hevel, as the Torah is at pains to point out, presented G-d with the choicest product he had raised, the best of his animals. Seeing that these two offerings became the cause of destruction on earth, G-d subsequently forbade the Jewish people to wear garments containing a mixture of linen and wool. (Tanchuma B’reshit, 9)
ויהי מקץ ימים, it was some time after Kayin had become a farmer tilling the soil, that he offered a gift to G-d. The Torah is deliberately vague about how much time had elapsed, writing only מקץ ימים, at the end of a number of years. It is reasonable to assume that the word ימים refers to years rather than days, as it is clear from Leviticus 25:29 that in that verse the word ימים represents the number of days that make up a year.
It would seem therefore, that after having worked the soil for a full year Kayin offered a gift to G-d, part of what he had harvested. He did this in the spot in which his father Adam had offered prayer and had offered a sacrifice of his own as an acknowledgement of his gratitude, his sons presumably having been in attendance. Although the Torah does not spell out the composition of Adam’s sacrifice, the Talmud in Shabbat 28 suggests that it included a one-horned ox, basing itself on Psalms 69,32 משור פר מקרן מפריס, "ox with horn and hooves," His sons imitated him, each one bringing a gift from what his labour had produced. The offering was meant to be an expression of man’s gratitude to G-d for the success of his endeavours.
מפרי, the Torah is vague about precisely what the offering consisted of, other than saying that it was part of the fruit produced by the earth. We know nothing about the quality or quantity of this offering. Seeing that when describing Hevel's offering the Torah adds the words: "from the firstborn of his sheep and from their best ones," it is reasonable to assume that Kayin's gift, by comparison, was stingy, in fact represented an insult to G-d rather than a grateful acknowledgment of G-d's part in making the earth produce a crop for him. This is why his offering was not welcome, was rejected.
Had Kayin at least brought of the best quality of the produce he had grown, the Torah would have mentioned this to his credit, just as it had done in the case of Hevel's offering. As a result of the philosophical contrast expressed by these two offerings, i.e. Kayin's flax and Hevel's wool, mixing these two fibres in one garment has been outlawed by the Torah for the Jewish people.
מפרי האדמה, "from the fruit of the earth." He should have brought of the first ripe fruit of the trees (of one or all of the seven species for which the land of Israel is famous instead of fruit grown in the earth). The Torah reveals Kayin's avarice, his stinginess. This is why the Torah refrains from mentioning that the fruit he brought were from the first ripe fruit of the earth.
The manner in which the Torah describes his offering is meant to convey that he selected the poorest type of produce, flax, rather than the best. Our sages in Tanchuma claim that he brought flax-seed. They derive this from the text seeing that the Torah mentions Kayin's offering only briefly while devoting more space to describing the offering of Hevel.
The Torah also stresses that Hevel brought from the firstlings of his sheep and their most perfect ones. Hevel brought firstlings from a category of product which was fit to serve as an offering for G-d. Kayin, on the other hand, offered produce which is not even fit to serve as an offering. Moreover, even the fruit which he did bring were the poorest quality of that category he could find. Bereshit Rabbah 22,8 compares Kayin to a bad land tenant who consumes the best produce of the owner’s land himself, giving the owner only the inferior part. מנחה לה'., "as a gift for G-d."
,ויבן שם אברהם את המזבח , "Avraham built the altar there." The letter ה at the beginning of the word המזבח, shows that a specific altar was meant, i.e. the altar. Rabbi Eliezer (below) sees in the letter ה, which is a definite article, an allusion to the altar which Adam had built and on which also Cain and Hevel had offered their respective sacrifices. The site of this altar had been known to be at Mount Moriah. This was also reputed to be the altar on which Noach had offered his thanksgiving to G-d after the deluge.
(ח) ר' שמעון אומר, באצבע הראה הב"ה לאברהם אבינו המזבח ואמר לו זה הוא המזבח והוא היה המזבח שהקריבו קין והבל והוא המזבח שהקריבו נח ובניו שנ' ויבן שם אברהם מזבח אין כתיב כאן אלא ויבן שם אברהם את המזבח הוא המזבח שהקריבו בו הראשונים.
Rabbi Simeon said: The Holy One, blessed be He, pointed out the altar with a finger to Abraham our father, and said to him: This is the altar. That was the altar whereon Cain and Abel sacrificed; it was the same altar whereon Noah and his sons sacrificed, as it is said, "And Abraham built the altar there" (Gen. 22:9). "And Abraham built an altar there" is not written here, but "And Abraham built the altar there." That was the altar whereon the first ones (of old) had sacrificed.
(8) Cain said to his brother Abel … and when they were in the field, Cain set upon his brother Abel and killed him.
Ancient versions, including the Targum, read "Come, let us go out into the field."
ויהי בהיותם בשדה. It was when they were both in the field. Why [did] the Torah want us to know that what followed occurred in the field?
(9) The LORD said to Cain, "Where is your brother Abel?" And he said, "I do not know. Am I my brother's keeper?"
Why did G-d have to ask Cain where his brother Abel was?
Why was Cain foolish enough to tell the One who knows everything that he did not know where his brother was?
Why did Cain add the gratuitous and provocative remark: "Am I my brother's keeper?"
(10) Then He said, "What have you done? Hark, your brother's blood cries out to Me from the ground!
Onkelos explains that the reason why here in particular the use of the plural mode is appropriate is the fact that by killing Hevel who had not yet been married and sired children, spilling his blood also meant spilling the blood of the children he would now never have. He may not even have had marital relations with his wife as yet, just as his brother Kayin had also not yet had marital relations with his wife until after he had murdered Hevel.
(11) Therefore, you shall be more cursed than the ground, which opened its mouth to receive your brother's blood from your hand. (12) If you till the soil, it shall no longer yield its strength to you. You shall become a ceaseless wanderer on earth."
מן האדמה, according to Rashi: "more than the previous curse decreed on earth as a result of Adam's having eaten from the tree of knowledge when it was punished for failing to have produced trees with edible trunks."
An alternate exegesis: the verse is to be understood as "you, Kayin, the farmer, are to have to work an earth cursed additionally when you work it, during this year, as it will not continue to yield its fruit for you in the year to follow; seeing that this is so, from now on you will be wandering on earth without permanent homestead, noting that you are cursed,"
ארור אתה מן האדמה אשר פצתה את פיה, "you are cursed from the earth which opened its mouth, etc." It is difficult to understand how the earth could be faulted. After all, the earth acts as receptacle for everything which is poured out upon it.
The answer given is that in this instance the earth deliberately tried to conceal the deed by swallowing all of Hevel’s blood (and body) so that not a trace of what happened there remained visible. Rashi explains the words ארור אתה מן האדמה, as meaning "you are cursed now even more than the first curse which had been decreed against the earth as a result of your father’s sin when he ate from the tree of knowledge."
Nature was modified also by the burial of the corpse of Abel. For a long time it lay there exposed, above ground, because Adam and Eve knew not what to do with it. They sat beside it and wept, while the faithful dog of Abel kept guard that birds and beasts did it no harm. On a sudden, the mourning parents observed how a raven scratched the earth away in one spot, and then hid a dead bird of his own kind in the ground. Adam, following the example of the raven, buried the body of Abel, and the raven was rewarded by God.
(13) Cain said to the LORD, "My punishment is too great to bear! (14) Since You have banished me this day from the soil, and I must avoid Your presence and become a restless wanderer on earth—anyone who meets me may kill me!" (15) The LORD said to him, "I promise, if anyone kills Cain, sevenfold vengeance shall be taken on him." And the LORD put a mark on Cain, lest anyone who met him should kill him.
Exile of either an individual or a nation is an indication that G-d has turned His countenance away from such an individual or such a nation. It means that such an individual or nation is no longer under the supervision of the Creator. Kayin’s anguished outcry was: "If this is so, what hope is there left for me? I am now at the mercy of every single creature!"
וישם ה' לקין אות, "G-d provided Kayin with a visible sign of identification to warn people not to kill him;" the Torah does not give details of the nature of this sign.
לבלתי הכות אותו, "not to slay him;" the need for this was because mankind had not yet been warned about the sin of murder.
This "sign" was the same as the tradition that by merely looking at a צדיק one can tell that he is a G-d-fearing person (compare Exodus 12,13: "this blood will be a sign for you." This means that the מצוה you have performed in preparing the paschal lamb will be accounted as a sign.) Such "signs" act as protection for the righteous against a variety of dangers.
(16) Cain left the presence of the LORD and settled in the land of Nod, east of Eden.