27:18-29 Jacob, with some difficulty, gained his point, and got the blessing. This blessing is in very general terms. No mention is made of the distinguishing mercies in the covenant with Abraham. This might be owing to Isaac having Esau in his mind, though it was Jacob who was before him. He could not be ignorant how Esau had despised the best things. Moreover, his attachment to Esau, so as to disregard the mind of God, must have greatly weakened his own faith in these things. It might therefore be expected, that leanness would attend his blessing, agreeing with the state of his mind.
Ge 27:28-46. The Blessing.
28. God give thee of the dew of heaven—To an Oriental mind, this phraseology implied the highest flow of prosperity. The copious fall of dew is indispensable to the fruitfulness of lands, which would be otherwise arid and sterile through the violent heat; and it abounds most in hilly regions, such as Canaan, hence called the "fat land" (Ne 9:25, 35).
plenty of corn and wine—Palestine was famous for vineyards, and it produced varieties of corn, namely, wheat, barley, oats, and rye.