18 He went to his father and said, "My father!" "Yes?" he said. "Which son are you?" 19 Jacob answered his father, "I'm your firstborn son Esau. I did what you told me. Come now; sit up and eat of my game so you can give me your personal blessing." 20 Isaac said, "So soon? How did you get it so quickly?" "Because your God cleared the way for me." 21 Isaac said, "Come close, son; let me touch you - are you really my son Esau?" 22 So Jacob moved close to his father Isaac. Isaac felt him and said, "The voice is Jacob's voice but the hands are the hands of Esau." 23 He didn't recognize him because his hands were hairy, like his brother Esau's. 24 he pressed him, "You're sure? You are my son Esau?" "Yes. I am."
Matthew Henry's Commentary on Genesis 27:18-24
Commentary on Genesis 27:18-29
(Read Genesis 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.