Sforno on Genesis 4:5/ספורנו על בראשית ד׳:ה׳

1ואל 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;

2ויחר, due to his jealousy of his brother,

3ויפלו פניו, he was downcast, being ashamed, feeling that G’d had publicly shamed him.