וַיִּגַּ֧שׁ יַעֲקֹ֛ב אֶל־יִצְחָ֥ק אָבִ֖יו וַיְמֻשֵּׁ֑הוּ וַיֹּ֗אמֶר הַקֹּל֙ ק֣וֹל יַעֲקֹ֔ב וְהַיָּדַ֖יִם יְדֵ֥י עֵשָֽׂו׃
Lalu Yakub mendekat kepada Ishak, ayahnya, dan Ishak merabanya serta berkata, “Suara ini suara Yakub, tetapi tangan ini tangan Esau.”
Rashi
THE VOICE OF JACOB, because he speaks in an entreating strain —“Arise I pray thee.” Esau, however, spoke in a harsh strain (v. 31) “Let my father arise” (Midrash Tanchuma, Toldot 11).
Chizkuni
.הקול קול יעקב, “the voice is distinctly the voice of Yaakov;” Yitzchok was not willing to base his judgment on the voice alone, as people are apt to disguise their voices on many occasions, both voluntarily and involuntarily. However he did not let this disturb him as the evidence of Yaakov’s arms and hands which were hairy were a much better indication that Esau indeed was standing in front of him. This was why he proceeded to give him a blessing that he had intended to give Esau.
Da'at Zekenim
הקול קול יעקב והידים ידי עשו, “the sound of the voice is that of Yaakov, whereas the feel of his hands is like that of the hands of Esau.” According to Midrash Rabbah, 69,20 the deeper meaning of these words is that Yitzchok knew that Esau could cause harm only with his hands, when near the victim, whereas Yaakov, whose weapon was prayer, could use that weapon over vast distances.