John Calvin Commentary Genesis 27:30

"And it came to pass, as soon as Isaac had made an end of 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." — Genesis 27:30 (ASV)

Jacob was yet scarce gone out. Here is also described the manner in which Esau was repulsed, a circumstance that contributed significantly to confirming the blessing for Jacob: for if Esau had not been rejected, it might have seemed that he was not deprived of the honor that nature had given him. But now Isaac declares that what he had done, by virtue of his patriarchal office, must be ratified.

Truly, it again becomes clear here that the primogeniture Jacob obtained at his brother's expense became his by a free gift: for if we compare their respective actions, Esau obeys his father, brings him the produce of his hunting, prepares for his father food obtained by his own labor, and speaks only the truth: in short, we find nothing in him that is not praiseworthy.

Jacob never leaves his home, substitutes a kid for venison, insinuates himself by many lies, and brings nothing that would truly commend him; instead, in many ways, he deserves censure. Therefore, it must be acknowledged that the cause of this event cannot be traced to works, but lies hidden in the eternal counsel of God.

Yet Esau is not unjustly reprobated, because those who are not governed by the Spirit of God cannot receive anything rightly. However, it must be firmly maintained that since the condition of all people is equal, if anyone is preferred to another, it is not because of his own merit, but because the Lord has gratuitously elected him.