What does Genesis 27:27 mean?
Jacob is disguised as his older twin brother, Esau, in a plot to steal a blessing from his father, Isaac (Genesis 27:6–10). Isaac's blindness and age make this possible, but not easy, so Jacob and his mother Rebekah conspire to fool Isaac (Genesis 27:1). To this point, it seems to have worked, though Isaac seems to have some lingering suspicions (Genesis 27:22).As Jacob comes near and kisses Isaac, the old man receives more confirmation that this must be Esau. His clothes carry the smell of the outdoors, of a field that the Lord has blessed. Esau loved to hunt and spend time in the fields, one of the things Isaac loved about his firstborn son (Genesis 25:28). Of course, this is part of the deception. Jacob's mother Rebekah had dressed him in Esau's clothes to make Jacob as convincing as possible to his blind father (Genesis 27:15). This particular trick works so well that Isaac immediately begins to confer the blessing on Jacob.
This specific part of Scripture does not indicate exactly what this blessing entails. It seems different from the covenant promises of God to Abraham and Isaac. Isaac will pass on that blessing to Jacob, in more precise words later on. At that point, he will have full knowledge, of the son to whom he is speaking. This blessing is more likely the customary blessing handed down from the father to his children in this era.
Since this boon comes from Isaac, however, as the patriarch of the chosen family of God at this point, this blessing will be more than the good wishes of a father. It will carry the weight of certainty. What Isaac prays in this blessing will absolutely come to pass in one form or another.