וַיֹּ֕אמֶר בָּ֥א אָחִ֖יךָ בְּמִרְמָ֑ה וַיִּקַּ֖ח בִּרְכָתֶֽךָ׃
이삭이 가로되 네 아우가 간교하게 와서 네 복을 빼앗았도다
Chizkuni
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.
Sforno
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.]