Genesis 27:4

“And make me savoury meat, such as I love, etc.] For, though he had lost his sight, he had not lost his taste, nor his appetite for savoury food: and bring [it] to me, that I may eat; this, was enjoined to make trial of his filial affection and duty to him, before he blessed him: that my soul may bless thee before I die; not only that he might do it with cheerfulness and vivacity, having eaten a comfortable meal, and being refreshed with it, but that having had proof of his son’s duty and affection to him, he might confer the blessing on him heartily: this blessing was not an ordinary and common one, but what parents used to bestow upon their children at the time of their death, or a little…”

“make . . . 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).”