(18) And he came unto his father, and said: ‘My father’; and he said: ‘Here am I; who are you, my son?’ (19) And Jacob said unto his father: ‘I am Esau your first-born; I have done according as you have bidden me. Arise, I pray you, sit and eat of my venison, that your soul may bless me.’ (20) And Isaac said unto his son: ‘How is it that you have found it so quickly, my son?’ And he said: ‘Because ADONAI your God sent me good speed.’ (21) And Isaac said unto Jacob: ‘Come near, I pray you, that I may feel you, my son, whether you be my very son Esau or not.’ (22) And Jacob went near unto Isaac his father; and he felt him, and said: ‘The voice is the voice of Jacob, but the hands are the hands of Esau.’ (23) And he discerned him not, because his hands were hairy, as his brother Esau’s hands; so he blessed him. (24) And he said: ‘Are you my very son Esau?’ And he said: ‘I am.’ (25) And he said: ‘Bring it near to me, and I will eat of my son’s venison, that my soul may bless you.’ And he brought it near to him, and he did eat; and he brought him wine, and he drank.
Torah: A Women's Commentary
Are you really my son Esau...Isaac is not only physically blind, but on a deeper level he refuses to recognize what would be clear to any parent. Can his knowledge of his children truly be so superficial that he can only distinguish between them physically?
וַיֹּאמֶר יִצְחָק אֶל בְּנוֹ מַה זֶּה מִהַרְתָּ לִמְצֹא בְּנִי (בראשית כז, כ), ...בְּשָׁעָה שֶׁאָמַר כִּי הִקְרָה ה' אֱלֹהֶיךָ לְפָנָי, אָמַר יִצְחָק יוֹדֵעַ אֲנִי שֶׁאֵין עֵשָׂו מַזְכִּיר שְׁמוֹ שֶׁל הַקָּדוֹשׁ בָּרוּךְ הוּא, זֶה מַזְכִּיר, אֵין זֶה עֵשָׂו אֶלָּא יַעֲקֹב,
Isaac then said to his son: "How is it that you were able to find [game] so quickly, my son...
The moment that he (Jacob) said: The Eternal your God made it happen for me, Isaac said: I know this is not Esau, for Esau would never call to mind the name of the Holy Blessed One. This tells me that this is not Esau, but Jacob.
Rabbi Norman Cohen in Self, Struggle & Change
If Isaac did recognize Jacob, why then is he pictured as asking his son a series of repetitive questions about his identity? “Who are you, my son?” “Come closer that I may feel you, my son—whether you are really my son Esau or not!” “Are you really my son Esau?” These piercing questions have another purpose. When Isaac asks Jacob, “Mi ata beni” (Who are you, my son?), he is giving him the opportunity to acknowledge who he is and what he is doing, since the decision is already made as to who will receive the blessing. He is really asking, “What is your makeup?” “What is your essential nature?” “Are you Jacob or Esau, or both?”
- sourced from "On Being Blind by Eric Contzius
Rabbi Lord Jonathan Sacks
Isaac fully understood the nature of his two sons. He loved Esau but this did not blind him to the fact that Jacob would be the heir of the covenant. Therefore Isaac prepared two sets of blessings, one for Esau, the other for Jacob. He blessed Esau (Gen. 27: 28-29) with the gifts he felt he would appreciate: wealth and power: “May God give you heaven’s dew and earth’s richness – an abundance of grain and new wine” – that is, wealth. “May nations serve you and peoples bow down to you. Be lord over your brothers, and may the sons of your mother bow down to you” – that is, power. These are not the covenantal blessings.
The covenantal blessings that God had given Abraham and Isaac were completely different. They were about children and a land. It is this blessing that Isaac later gave Jacob before he left home (Gen. 28: 3-4): “May God Almighty bless you and make you fruitful and increase your numbers until you become a community of peoples” – that is, children. “May He give you and your descendants the blessing given to Abraham, so that you may take possession of the land where you now reside as a foreigner, the land God gave to Abraham” – that is, land. This was the blessing Isaac had intended for Jacob all along. There was no need for deceit and disguise.