Kli Yakar develops the contrast between Jacob's voice and Esau's hands and relates it to the differing spiritual modes represented by the two brothers in the blessing narrative.
הַקּוֹל קוֹל יַעֲקֹב וְהַיָּדַיִם יְדֵי עֵשָׂו. לֹא הָיָה יָכוֹל לוֹמַר ״הַקּוֹל שֶׁל יַעֲקֹב וְהַיָּדַיִם שֶׁל עֵשָׂו״, דְּאִם כֵּן הָיָה מַשְׁמַע שֶׁהוּא שָׁפַט מִצַּד הַקּוֹל שֶׁזֶּה וַדַּאי יַעֲקֹב, וּמִצַּד הַיָּדַיִם שֶׁזֶּה וַדַּאי עֵשָׂו, וְזֶה דָּבָר נִמְנָע, שֶׁאִם הוּא יַעֲקֹב אֵינוֹ עֵשָׂו, וְאִם הוּא עֵשָׂו אֵינוֹ יַעֲקֹב. אֲבָל בֵּאוּר הָעִנְיָן כָּךְ הוּא, שֶׁאָמַר הַקּוֹל דּוֹמֶה לַקּוֹל שֶׁל יַעֲקֹב, וְאוּלַי זֶה מִתְנַכֵּר בְּקוֹלוֹ וְהָאֱמֶת שֶׁזֶּה עֵשָׂו, וּמִתְנַכֵּר לְדַבֵּר בִּלְשׁוֹן תַּחֲנוּנִים לוֹמַר שֶׁהוּא הָגוּן לְקַבֵּל הַבְּרָכוֹת. אוֹ הַיָּדַיִם דּוֹמִין לִידֵי עֵשָׂו וְזֶהוּ יַעֲקֹב, וּמִתְנַכֵּר בַּעֲשׂוֹתוֹ יָדָיו שְׂעִירוֹת כְּדֵי שֶׁאֶחְשׁוֹב שֶׁזֶּה עֵשָׂו. וּמַה שֶּׁנֶּאֱמַר ״וְהַיָּדַיִם״ בְּוָא״ו, הוּא מִלְּשׁוֹן ״וּמַכֵּה אָבִיו וְאִמּוֹ״ (שמות כא:טו) שֶׁפֵּרוּשׁוֹ ״אוֹ אִמּוֹ״, כָּךְ אָמַר ״אוֹ הַיָּדַיִם דּוֹמִין לִידֵי עֵשָׂו״. וְאִם תִּרְצֶה לוֹמַר, וָי״ו שֶׁל ״וְהַיָּדַיִם״ הוּא וָי״ו הָעִטּוּף, נוּכַל לוֹמַר שֶׁחָשַׁב יִצְחָק אוּלַי אֵיזֶה אִישׁ נָכְרִי מִתְנַכֵּר בִּשְׁנֵיהֶם, בַּקּוֹל וּבַיָּדַיִם. וּלְסוֹף שָׁפַט יִצְחָק בְּשִׂכְלוֹ שֶׁהַיָּדַיִם מַכְרִיעִים יוֹתֵר מִן הַקּוֹל, כִּי מַה שֶּׁעֵשָׂו מִתְנַכֵּר לְדַבֵּר בִּלְשׁוֹן תַּחֲנוּנִים הוּא יוֹתֵר קָרוֹב לִשְׁמֹעַ מִמַּה שֶּׁנֹּאמַר שֶׁיַּעֲקֹב עָשָׂה אֶת יָדָיו שְׂעִירוֹת, אוֹ אִישׁ נָכְרִי עָשָׂה כֵן. כִּי אֵיךְ יוּכַל לְשַׁעֵר יַעֲקֹב, וְכָל שֶׁכֵּן אֵיזוֹ אָדָם אַחֵר, לַעֲשׂוֹת יָדָיו שְׂעִירוֹת עַל זֶה הַשִּׁעוּר, עַד שֶׁיִּהְיוּ כִּידֵי עֵשָׂו מַמָּשׁ, דּוֹמֶה לָהֶם מִכָּל צַד? זֶהוּ שֶׁאָמַר ״וְלֹא הִכִּירוֹ כִּי הָיוּ יָדָיו כִּידֵי עֵשָׂו אָחִיו שְׂעִרֹת״ (בראשית כז:כג), דּוֹמֶה לָהֶם מִכָּל צַד. וּמִי יוּכַל לְשַׁעֵר זֶה שֶׁלֹּא יִסְכַּל בְּאֵיזוֹ דִּמְיוֹן? וְכִי הָיוּ יְדֵי עֵשָׂו בְּיָדוֹ וְלָקַח מֵהֶם הַצִּיּוּר? זֶה דָּבָר נִמְנָע. וְרז״ל דָּרְשׁוּ מִפָּסוּק זֶה (בראשית רבה סה, כ) שֶׁכָּל זְמַן שֶׁיַּעֲקֹב מְצַפְצֵף בְּקוֹלוֹ, אֵין יְדֵי עֵשָׂו שׁוֹלְטוֹת בּוֹ. אַף עַל פִּי שֶׁפְּשׁוּטוֹ מַשְׁמַע שֶׁיִּצְחָק אָמַר כֵּן וְהָיָה סָבוּר שֶׁזֶּה עֵשָׂו, וְעוֹד מַה עִנְיָן זֶה לִבְרָכָה זוֹ, מִכָּל מָקוֹם כָּךְ פֵּרוּשׁוֹ: כִּי דַּעַת יִצְחָק הָיָה לְבָרֵךְ אֶת עֵשָׂו בְּבִרְכַת ״הֱוֵי גְבִיר לְאַחֶיךָ״ (בראשית כז, כט), הַיְינוּ לְיַעֲקֹב, שֶׁיִּהְיוּ יְדֵי עֵשָׂו שׁוֹלְטוֹת בּוֹ. וְהִטִּיל תְּנַאי בַּדָּבָר לוֹמַר, דַּוְקָא אִם יַעֲקֹב לֹא יְצַפְצֵף בְּקוֹלוֹ בְּבָתֵּי כְּנֵסִיּוֹת וּמִדְרָשׁוֹת, אֲבָל לֹא בִּזְמַן שֶׁיְּצַפְצֵף בְּקוֹלוֹ, כִּי הַקּוֹל דּוֹחֶה הַיָּדַיִם. וְרָמַז זֶה בְּמַה שֶּׁהִקְדִּים הַקּוֹל אֶל הַיָּדַיִם, כִּי יֵשׁ לְהַקְשׁוֹת: הֲלֹא יִצְחָק הָלַךְ יוֹתֵר אַחַר הַיָּדַיִם מִמַּה שֶּׁהָלַךְ אַחַר הַקּוֹל, אִם כֵּן הָיָה לְהַקְדִּים הַיָּדַיִם? כִּי מָצִינוּ בְּכָל מָקוֹם שֶׁהַמֻּקְדָּם דּוֹחֶה אֶת הַמְאֻחָר, כְּמוֹ שֶׁיִּתְבָּאֵר בְּעֶזְרַת ה׳ (שמות לה, ב) פָּרָשַׁת וַיַּקְהֵל, עַל מַה שֶּׁפֵּרַשׁ רַשִׁ״י ״הִקְדִּים שַׁבָּת לַמִּשְׁכָּן לוֹמַר לְךָ שֶׁאֵין מְלֶאכֶת הַמִּשְׁכָּן דּוֹחָה אֶת הַשַּׁבָּת״, עַיֵּן שָׁם (שמות לה, ב). אֶלָּא וַדַּאי שֶׁלְּכָךְ הִקְדִּים הַקּוֹל שֶׁל יַעֲקֹב לִידֵי עֵשָׂו, לוֹמַר לְךָ שֶׁהַקּוֹל דּוֹחֶה אֶת הַיָּדַיִם. וְאֵיזֶהוּ? הֱוֵי אוֹמֵר זֶה קוֹלוֹ שֶׁל יַעֲקֹב בְּבָתֵּי מִדְרָשׁוֹת. וּבְזֶה מְתוֹרָץ מַה שֶּׁרֹב הָעוֹלָם מַקְשִׁים עַל אַגָּדָה זוֹ, שֶׁמַּשְׁמָעוּת הַכָּתוּב הוּא שֶׁשְּׁנֵיהֶם שׁוֹלְטוֹת כְּאֶחָד, וְזֶה הֵפֶךְ מִדִּבְרֵי הַמִּדְרָשׁ. וּבָאוּ עַל קוּשְׁיָא זוֹ שִׁנּוּיִים דְּחוּקִים, וּמַה שֶּׁכָּתַבְתִּי הוּא נָכוֹן וְיָקָר.
The voice is the voice of Jacob, and the hands are the hands of Esau. He [Isaac] could not say “the voice OF Jacob and the hands OF Esau,” because then it would have implied that he judged definitively from the voice that this was certainly Jacob, and from the hands that this was certainly Esau — and this would be impossible, for if he is Jacob he cannot be Esau, and if he is Esau he cannot be Jacob. Rather, the explanation of the matter is thus: he was saying that the voice resembles the voice of Jacob, and perhaps this person is disguising his voice, and in truth it is Esau, who is disguising himself by speaking in pleading tones to show that he is worthy of receiving the blessings. Or [alternatively], the hands resemble the hands of Esau but it is Jacob, who is disguising himself by making his hands hairy so that I [Isaac] would think this is Esau. And regarding why it says AND the hands with a vav [conjunction], this is similar to the phrase and [one who] strikes his father and mother where the meaning is “or his mother” — similarly here, he is saying “or the hands resemble the hands of Esau.” And if you want to say that the vav [Hebrew letter] in vehayadayim [and the hands] is a conjunctive vav, we can say that Isaac thought perhaps some stranger was disguising himself in both aspects — in voice and hands. But ultimately, Isaac reasoned that the hands were more convincing than the voice, because it is more plausible to believe that Esau was pretending to speak in a pleading tone than to believe that Jacob made his hands hairy or that some stranger did so. For how could Jacob, and certainly how could any other person, make their hands hairy to such a degree that they would be exactly like Esau’s hands, similar to them in every way? This is what is meant by and he did not recognize him because his hands were like the hands of Esau his brother, hairy — similar to them in every aspect. And who could possibly replicate this without making some error in the likeness? For were Esau’s hands in his possession to take their exact form from them? This would be impossible. Our Sages interpreted from this verse (Bereishit Rabbah 65:20) that as long as Jacob’s voice is heard [literally: chirping], the hands of Esau have no power over him. Although the simple meaning suggests that Isaac said this thinking it was Esau, and furthermore, what does this have to do with this blessing? Nevertheless, this is its explanation: Isaac’s intention was to bless Esau with the blessing be a master to your brothers — meaning over Jacob — that Esau’s hands would have power over him. However, he attached a condition to this, saying this would only be if Jacob is not using his voice in synagogues and study halls, but not when his voice is heard, because the voice repels the hands. He hinted at this by mentioning the voice before the hands, for one could ask: didn’t Isaac rely more on the hands than on the voice? If so, he should have mentioned the hands first, since we find everywhere that what comes first pushes away what comes after, as will be explained, God willing, later in Parashat Vayakhel regarding Rashi’s explanation of why Shabbat is mentioned before the Tabernacle — to tell you that the work of the Tabernacle does not override Shabbat (see there, Exodus 35:2). Rather, surely this is why he mentioned Jacob’s voice before Esau’s hands — to tell you that the voice pushes away the hands. And which voice is this? You must say it is Jacob’s voice in the study halls. This resolves what most people ask about this aggadah, as the verse seems to suggest that both [the voice and hands] rule simultaneously, which contradicts the Midrash’s words. Many forced answers have been given to this question, but what I have written is correct and precious.