창세기 4:5의 주석

ואל קין ואל מנחתו לא שעה, He did not turn to Kayin the donor, as he was not pleasing in the eyes of G’d; He also did not turn with favour to his offering seeing the nature of the offering was not designed to make it welcome;

ויחר לקין מאד, Cain was very angry. The emotion חרון אף indicates that a person feels superior, whereas the expression נפילת אפים indicates that one feels inferior. Cain felt angry at the superiority achieved by his younger brother. He felt inferior towards his brother thinking that the superior quality of his brother's offering was the cause that his own offering had not been accepted. He believed that this was the reason he had suffered a loss of image in the eyes of G'd.

ואל קין ואל מנחתו לא שעה, but to Kayin and to his offering G’d did not turn benevolently. His intention had not been good and pure; G’d does not need to accept gifts proffered reluctantly, as He is not in need of them. How did Kayin find out that G’d had not looked with favour on his offering? He found out that Hevel’s offering had been accepted, fire descending on it from heaven and consuming it. Nothing of that kind happened to Kayin’s offering. This caused Kayin dismay and anger and his face became downcast. The expression נפלו פניו, describes that someone feels insulted, depressed..