פֶּרֶא אָדָם לְשׁוֹן רַשִׁ"י (רש"י על בראשית ט"ז:י"ב) אוֹהֵב מִדְבָּרוֹת לָצוּד חַיּוֹת, כְּמוֹ שֶׁכָּתוּב (בראשית כ"א:כ') "וַיֵּשֶׁב בַּמִּדְבָּר וַיְהִי רֹבֶה קַשָּׁת". "יָדוֹ בַּכֹּל", לִסְטִים. "וְיַד כֹּל בּוֹ", הַכֹּל שׂוֹנְאִין אוֹתוֹ וּמִתְגָּרִין בּוֹ. וְהַנָּכוֹן כִּי "פֶּרֶא אָדָם" סָמוּךְ, שֶׁיִּהְיֶה אִישׁ פֶּרֶא לִמֻּד מִדְבָּר, יֵצֵא בְּפָעֳלוֹ מְשַׁחֵר לַטֶּרֶף, וְיִטְרֹף הַכֹּל וְהַכֹּל יִטְרְפוּהוּ. וְהָעִנְיָן עַל זַרְעוֹ שֶׁיִּגְדַּל וְיִהְיוּ לָהֶם מִלְחָמוֹת עִם כָּל הָעַמִּים. וְרַבִּי אַבְרָהָם אָמַר (אבן עזרא על בראשית ט"ז:י"ב), "יָדוֹ בַּכֹּל", שֶׁיְּנַצַּח מִתְּחִלָּה כָּל הַגּוֹיִם, וְאַחַר כֵּן "יַד כֹּל בּוֹ", שֶׁיְּנֻצַּח בַּסּוֹף, "וְעַל פְּנֵי כָל אֶחָיו" שֶׁהֵם בְּנֵי קְטוּרָה, "יִשְׁכֹּן", שֶׁיִּגְדַּל זַרְעוֹ מֵהֶם: ‘PERE ADAM.’ Rashi comments: “One who loves the deserts364The word pere is thus, according to Rashi, synonymous with “desert,” as it says peraim bamidbar (Job 24:5). Pere adam is thus: “a man who loves the desert.” (Mizrachi.) [and] to hunt wild animals, as it is written, And he dwelt in the wilderness and became an archer.365Further, 21:20. His hand shall be against every man. This means that he will be a highway man. And every man’s hand against him. Everyone will hate him and attack him.”
The correct interpretation is that pere adam is a construct form, meaning that he will be a wild-ass man accustomed to the wilderness, going forth to his work, seeking for food, devouring all and being devoured by all. The subject pertains to his children who will increase, and they will have wars with all the nations.
Rabbi Abraham ibn Ezra said: “His hand shall be against every man in that he will be victorious at first over all nations, and afterwards, every man’s hand shall be against him, meaning that he will be vanquished in the end. And in the face of all his brethren, who are the sons of Keturah,366Further, 25:1-4. he should dwell, meaning that Ishmael’s children will outnumber those of Keturah.”