A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
gen 27:1INFIRMITY OF ISAAC. (Gen. 27:1-27)
when Isaac was old, and his eyes were dim--He was in his hundred thirty-seventh year; and apprehending death to be near, Isaac prepared to make his last will--an act of the gravest importance, especially as it included the conveyance through a prophetic spirit of the patriarchal blessing.
gen 27:4make . . . savory meat--perhaps to revive and strengthen him for the duty; or rather, "as eating and drinking" were used on all religious occasions, he could not convey the right, till he had eaten of the meat provided for the purpose by him who was to receive the blessing [ADAM CLARKE] (compare Gen 18:7).
that my soul may bless thee--It is difficult to imagine him ignorant of the divine purpose (compare Gen 25:23). But natural affection, prevailing through age and infirmity, prompted him to entail the honors and powers of the birthright on his elder son; and perhaps he was not aware of what Esau had done (Gen 25:34).
gen 27:6Rebekah spake unto Jacob--She prized the blessing as invaluable; she knew that God intended it for the younger son [Gen 25:23]; and in her anxiety to secure its being conferred on the right object--on one who cared for religion--she acted in the sincerity of faith; but in crooked policy--with unenlightened zeal; on the false principle that the end would sanctify the means.
gen 27:11Jacob said, Esau my brother is a hairy man--It is remarkable that his scruples were founded, not on the evil of the act, but on the risk and consequences of deception.
gen 27:13and his mother said unto him, Upon me be thy curse--His conscience being soothed by his mother, preparations were hastily made for carrying out the device; consisting, first, of a kid's flesh, which, made into a ragout, spiced with salt, onions, garlic, and lemon juice, might easily be passed off on a blind old man, with blunted senses, as game; second, of pieces of goat's skin bound on his hands and neck, its soft silken hair resembling that on the cheek of a young man; third, of the long white robe--the vestment of the first-born, which, transmitted from father to son and kept in a chest among fragrant herbs and perfumed flowers used much in the East to keep away moths--his mother provided for him.
gen 27:18he came unto his father--The scheme planned by the mother was to be executed by the son in the father's bedchamber; and it is painful to think of the deliberate falsehoods, as well as daring profanity, he resorted to. The disguise, though wanting in one thing, which had nearly upset the whole plot, succeeded in misleading Isaac; and while giving his paternal embrace, the old man was roused into a state of high satisfaction and delight.
gen 27:27the smell of my son is as of a field--The aromatic odors of the Syrian fields and meadows, often impart a strong fragrance to the person and clothes, as has been noticed by many travellers.
gen 27:28THE BLESSING. (Gen. 27:28-46)
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" (Neh 9:25, Neh 9:35).
plenty of corn and wine--Palestine was famous for vineyards, and it produced varieties of corn, namely, wheat, barley, oats, and rye.
gen 27:29Let people serve thee--fulfilled in the discomfiture of the hostile tribes that opposed the Israelites in the wilderness; and in the pre-eminence and power they attained after their national establishment in the promised land. This blessing was not realized to Jacob, but to his descendants; and the temporal blessings promised were but a shadow of those spiritual ones, which formed the grand distinction of Jacob's posterity.
gen 27:30Esau came in from his hunting--Scarcely had the former scene been concluded, when the fraud was discovered. The emotions of Isaac, as well as Esau, may easily be imagined--the astonishment, alarm, and sorrow of the one; the disappointment and indignation of the other. But a moment's reflection convinced the aged patriarch that the transfer of the blessing was "of the Lord," and now irrevocable. The importunities of Esau, however, overpowered him; and as the prophetic afflatus was upon the patriarch, he added what was probably as pleasing to a man of Esau's character as the other would have been.
gen 27:39Behold, thy dwelling shall be the fatness of the earth--The first part is a promise of temporal prosperity, made in the same terms as Jacob's [Gen 27:28] --the second part refers to the roving life of hunting freebooters, which he and his descendants should lead. Though Esau was not personally subject to his brother, his posterity were tributary to the Israelites, till the reign of Joram when they revolted and established a kingdom of their own (Kg2 8:20; Ch2 21:8-10).
gen 27:41Esau hated Jacob--It is scarcely to be wondered at that Esau resented the conduct of Jacob and vowed revenge.
The days of mourning for my father are at hand--a common Oriental phrase for the death of a parent.
gen 27:42these words of Esau were told Rebekah--Poor woman! she now early begins to reap the bitter fruits of her fraudulent device; she is obliged to part with her son, for whom she planned it, never, probably, seeing him again; and he felt the retributive justice of heaven fall upon him heavily in his own future family.
gen 27:45Why should I be deprived of you both?--This refers to the law of Goelism, by which the nearest of kin would be obliged to avenge the death of Jacob upon his brother.
gen 27:46Rebekah said to Isaac--Another pretext Rebekah's cunning had to devise to obtain her husband's consent to Jacob's journey to Mesopotamia; and she succeeded by touching the aged patriarch in a tender point, afflicting to his pious heart--the proper marriage of their younger son.