the double blessing

  וַיֹּ֗אמֶר הַקֹּל֙ ק֣וֹל יַעֲקֹ֔ב וְהַיָּדַ֖יִם יְדֵ֥י עֵשָֽׂו

If the kol was kol Yaakov but the yadyim indicated that it was Eisav, then Yitzchak should have been perplexed.  Was it Yaakov or was it Eisav?  Why then did he proceed to give the brachos without first figuring out what was going on?

The Beis haLevi has a famous clever answer to this, but I wanted to share with you the approach of R' Reuvain Katz, the Degel Reuvain, in his sefer on chumash.  

He writes that in reality, the bracha of Yitzchak was two blessings in one.  Firstly, a bracha of success in olam ha'zeh:

 וְיִֽתֶּן־לְךָ֙ הָאֱלֹהִ֔ים מִטַּל֙ הַשָּׁמַ֔יִם וּמִשְׁמַנֵּ֖י הָאָ֑רֶץ וְרֹ֥ב דָּגָ֖ן וְתִירֹֽשׁ

And secondly, a bracha of ruchniyus

 הֱוֵ֤ה גְבִיר֙ לְאַחֶ֔יךָ וְיִשְׁתַּחֲו֥וּ לְךָ֖ בְּנֵ֣י אִמֶּ֑ךָ אֹרְרֶ֣יךָ אָר֔וּר וּֽמְבָרְכֶ֖יךָ בָּרֽוּךְ

Which in effect was the bracha of Avraham Avinu from back in Lech Lecha. 

Yitzchak may not have known the full extent of Eisav's wickedness, but even so, he never intended this second bracha of ruchniyus to be his.  He knew that Rivka had been told that  וְרַ֖ב יַעֲבֹ֥ד צָעִֽיר, and therefore he could never have promised Eisav  הֱוֵ֤ה גְבִיר֙ לְאַחֶ֔יךָ ,contrary to the dvar Hashem.  What he intended was that Eisav should receive that first bracha, the bracha of success in olam ha'zeh, and Eisav would use that to help Yaakov, who would receive the second bracha and remain the yosheiv ohalim.  This would be the perfect Yisachar/Zevulun partnership.    

When Yitzchak heard Yaakov's voice but then felt the hairy skin of Eisav, הַקֹּל֙ ק֣וֹל יַעֲקֹ֔ב וְהַיָּדַ֖יִם יְדֵ֥י עֵשָֽׂו, he thought both brothers had come in together to serve him.  This was perfect -- now he could bless both brothers at once, each with the bracha appropriate for his needs.  

When Yitzchak realized that someone other than Eisav had taken the first bracha, he exclaimed

וַיֶּחֱרַ֨ד יִצְחָ֣ק חֲרָדָה֮ גְּדֹלָ֣ה עַד־מְאֹד֒ וַיֹּ֡אמֶר מִֽי־אֵפ֡וֹא ה֣וּא הַצָּֽד־צַ֩יִד֩ וַיָּ֨בֵא לִ֜י וָאֹכַ֥ל מִכֹּ֛ל בְּטֶ֥רֶם תָּב֖וֹא וָאֲבָרְכֵ֑הוּ גַּם־בָּר֖וּךְ יִהְיֶֽה׃

The Midrash comments on the words גַּם־בָּר֖וּךְ יִהְיֶֽה that we see that Yitzchak gave his stamp of approval to Yaakov's blessing irrespective of any trickery.  So how do you explain the first part of the pasuk?  R' Katz explains that the Midrash is speaking about the second bracha which was meant all along for Yaakov; on that, גַּם־בָּר֖וּךְ יִהְיֶֽה.  The first part of the pasuk is talking about the first bracha that had been meant for Eisav, and that bracha Yitzchak was worried had gone to the wrong person.

Look at how the possessive repeats itself in these pesukim:

וַיֹּ֕אמֶר בָּ֥א אָחִ֖יךָ בְּמִרְמָ֑ה וַיִּקַּ֖ח בִּרְכָתֶֽךָ -- Yaakov took YOUR bracha 

 וַיֹּ֡אמֶר הֲכִי֩ קָרָ֨א שְׁמ֜וֹ יַעֲקֹ֗ב וַֽיַּעְקְבֵ֙נִי֙ זֶ֣ה פַעֲמַ֔יִם אֶת־בְּכֹרָתִ֣י לָקָ֔ח וְהִנֵּ֥ה עַתָּ֖ה לָקַ֣ח בִּרְכָתִ֑י -- he took MY bracha

Eisav is so upset not because Yaakov got a blessing -- why should he not? -- but because Yaakov got the blessing that was supposed to go to him.  What business does Yaakov, the yosehiv ohalim, have with a bracha for material success?  

This is why Yitzchak responded to Eisav's plea to give him a bracha as well that הֵ֣ן גְּבִ֞יר שַׂמְתִּ֥יו לָךְ֙ וְאֶת־כׇּל־אֶחָ֗יו נָתַ֤תִּי לוֹ֙ לַעֲבָדִ֔ים וְדָגָ֥ן וְתִירֹ֖שׁ סְמַכְתִּ֑יו וּלְכָ֣ה אֵפ֔וֹא מָ֥ה אֶֽעֱשֶׂ֖ה בְּנִֽי.  Yitzchak was saying that he already gave Yaakov the blessing of olam ha'zeh as well, the bracha that had been meant for Eisav.  He could not give Eisav a bracha of ruchniyus, so what else was left to give?