John Chrysostom

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.