And it came to pass, as soon as Isaac had finished blessing Jacob, and Jacob was yet scarce gone out from the presence of Isaac his father, that Esau his brother came in from his hunting.
Read Chapter 27
Ambrose of Milan
Afterward, when the blessing had been pronounced, the elder brother arrived. By this it is revealed that the kingdom was predestined to be bestowed on the church rather than on the synagogue but had secretly entered the synagogue so that sin might abound, and, when sin had abounded, that grace might also abound. At the same time, it would be clear that the candidate for the kingdom of heaven must be quick to carry off the blessing and to appropriate the prerogative for which he has been recommended. On this account the younger son was not blamed by his father but praised, for Isaac says, “Your brother came deceitfully and received your blessing.” For deceit is good when the plunder is without reproach. Now the plunder of piety is without reproach, because “from the days of John the kingdom of heaven suffers violence, and the violent bear it away.” Our fathers celebrated the Passover in haste and ate the lamb in haste, not making delay, and the holy Joseph summoned his brother Benjamin ...
The other one, you see, comes along in the evening, and brings what his father ordered, and finds his brother has been blessed instead of himself and is not blessed with a second blessing. Because those two men were two peoples. One blessing signifies the unity of the church. But they are two peoples …. But the two peoples who belong to Jacob are represented in other ways. You see, our Lord Jesus Christ, who had come to Jews and Gentiles, was repudiated by the Jews, who belonged to the elder son. However, he chose some of them who belonged to the younger son, who had begun to desire and understand the Lord’s promises, not taking that land they desired materialistically but spiritually desiring that city where no one is materially born, because in it no one either materially or spiritually dies.
Fear. Septuagint, "Isaac was wrapt into an ecstasy exceedingly great "during which God explained to him the meaning of what had happened, that he might not think of revoking his blessing. (St. Augustine, q. 80.) He permitted Isaac to be in darkness respecting this affair, that it might be more manifest, that the will of man had no part in preferring Jacob; (St. Chrysostom, hom. 53.) and that Esau might not direct his rage against his father. (Worthington)