John Calvin Commentary Genesis 27:14

"And he went, and fetched, and brought them to his mother. And his mother made savory food, such as his father loved." — Genesis 27:14 (ASV)

And he went and fetched. Although it is probable that Jacob was not only influenced by a desire to yield obedience to the authority of his mother, but was also persuaded by her reasonings, he still sinned by overstepping the bounds of his vocation. When Rebekah had taken the blame upon herself, she told him, doubtless, that injury was done to no one, because Jacob was not stealing away another’s right, but only seeking the blessing which was decreed to him by the celestial oracle.

It seemed a fair and probable excuse for the fraud that Isaac, unless he was deceived, was prepared to invalidate the election of God. Therefore Jacob, instead of simply departing from what was right in submission to his mother, was rather obeying the word of God. In the meantime (as I have said), this particular error was not free from blame, because the truth of God was not to be aided by such falsehoods.

The paternal benediction was a seal of God’s grace, I confess it; but she ought to have waited instead until God brought relief from heaven, by changing the mind and guiding the tongue of Isaac, rather than have attempted what was unlawful. For if Balaam, who prostituted his venal tongue, was constrained by the Spirit, contrary to his own wish, to bless the elect people, whom he would rather have devoted to destruction (Numbers 22:12), how much more powerfully would the same Spirit have influenced the tongue of holy Isaac, who was not a mercenary man, but one who desired faithfully to obey God, and was only carried away by error in the opposite direction? Therefore, although overall, faith shone preeminently in holy Jacob, yet in this respect he bears blame for his rashness, because he distrusted the providence of God, and fraudulently gained possession of his father’s blessing.