Commentary for Genesis 27:35

במרמה WITH SUBTLETY — with cleverness (cf. Onkelos).

ויקח ברכתך, the blessing that would have been appropriate as suitable and effective for you. The blessing which Yaakov had been given (mistakenly), concerned matters of importance in our material life on this earthy both while in our own land or in the Diaspora. The reason Yitzchok had phrased it thus was because the blessing G’d had given Avraham and which was to be given to one of Yitzchok’s children was not appropriate for Esau. [the latter blessing was given to Yaakov in 28,4 so that Yaakov indeed had secured both blessings. Ed.]

ויאמר...במרמה, by making his hands appear hairy.

בא אחיך במרמה, “your brother came using trickery.” Even though initially, Yitzchok had asked: ”who then is the one who came, etc.”, having had the revelation from the Holy Spirit, now he knew for certain that it had been Yaakov who had come and snatched the blessing from his father.

With cleverness. Otherwise, [if it meant deceit], why should he be blessed?

ויקח ברכתך, “he has taken the blessing that I meant to bestow upon you.” [Yitzchok meant that the reason that he had wanted to bestow this blessing on Esau originally, was only because biologically speaking,] for he had been the firstborn.