Genesis 4:6

God wishes to defuse the wild frenzy and remove the anger by means of his words. You see, he observed the stages of Cain's thinking and realized the savagery of his deadly intention; so he intends at this early stage to sedate his thinking and bring repose to his mind by placing his brother subject to him and not undermining his authority. But even despite such great concern and such potent remedies, Cain gained nothing from the experience. Such was the degree of difference in their attitudes and the excess of evil intent.

God said to Cain, "Why are you angry, and why is your face gloomy?" Instead of being filled with anger, you ought to be filled with distress. Instead of your face being gloomy, tears ought to be flowing from your eyes.

Consider, I ask you, dearly beloved, the ineffable considerateness in his care when he saw Cain under assault, so to speak, from the passion of envy, see how out of fidelity to his own goodness he applied various remedies to him so that he might be quickly plucked from the water and not be drowned. "'For what reason are you annoyed? For what reason has your face fallen?"' Why on earth, he is saying, are you overcome with such resentment as to show the extent of your displeasure on your face? "'For what reason has your face fallen?'" Why has this event so affected you? Why have you not considered what your obligation was? You weren't making your offering to a human being, capable of being deceived, were you. Did you not realize that I wasn't looking for some offering or other of yours, but for the pure intention of the offerer? "'For what reason are you annoyed? For what reason has your face fallen? Is it not true that, even if you make your offering correctly but fail to choose the offering correctly, you commit sin?" That is to say, while your having the idea of making an offering was commendable, still your not choosing the offering correctly led to the rejection of the offering. I he one who makes an offering to God, you know, must show great care in the choice, and the greater the difference between the recipient and the offerer, the greater the distinction you should lend to your choice. You, however, gave no thought to these matters but simply offered whatever came to hand; hence they in turn could not be judged acceptable. You see, just as your intention in making the offering did not make allowance for the difference in status, and so caused the offering presented by you to be rejected; in like manner, your brother's intention, which happened to be correct and revealed great care in the choice, caused his gifts to be acceptable.

(Verse 6.) And the Lord said to Cain: Why is your face downcast? If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it. We are compelled to linger longer on each individual. For even now the meaning is very different in the Hebrew than in the translators of the Septuagint. For the Lord said to Cain: Why are you angry? Why is your face downcast?

And the Lord said to him: Why are you angry, and why has your countenance fallen? If you do well, will you not be accepted? But if you do not do well, sin lies at the door?