Ramban develops the battle with Amalek as a sign and paradigm: Moshe’s hands represent faith and divine aid, while the ongoing memory and war with Amalek reflect a historical-spiritual antagonism that is not simply erased in one moment.
וְטַעַם וַיְהִי יָדָיו אֱמוּנָה שֶׁהָיוּ עוֹמְדוֹת וְקַיָּמוֹת בְּרוֹמְמוּתָן, כִּלְשׁוֹן "וַאֲמָנָה עַל הַמְשֹׁרְרִים דְּבַר יוֹם בְּיוֹמוֹ" (נחמיה יא כג), וְכֵן "אֲנַחְנוּ כּוֹרְתִים אֲמָנָה" (שם י יא), דָּבָר קַיָּם בִּבְרִית, וְכֵן "הַיָּתֵד הַתְּקוּעָה בְּמָקוֹם נֶאֱמָן" (ישעיה כב כג), חָזָק: וְעַל דֶּרֶךְ הָאֱמֶת, נָשָׂא עֶשֶׂר אֶצְבָּעוֹת לְרוּם הַשָּׁמַיִם לִרְמֹז עַל עֶשֶׂר סְפִירוֹת לְדָבְקָה בֶּאֱמוּנָה הַנִּלְחָם לְיִשְׂרָאֵל, וּבְכָאן נִתְבָּאֵר עִנְיַן נְשִׂיאוּת כַּפַּיִם בְּבִרְכַּת כֹּהֲנִים וְסוֹדוֹ: כִּי יָד עַל כֵּס יָהּ יָדוֹ שֶׁל הקב"ה הוּרְמָה לִשָּׁבַע בְּכִסְאוֹ לִהְיוֹת לוֹ מִלְחָמָה וְאֵיבָה בַּעֲמָלֵק עוֹלָמִית. וּמַהוּ כֵּס וְלֹא נֶאֱמַר כִּסֵּא, וְאַף הַשֵּׁם נֶחֱלַק לְחֶצְיוֹ, נִשְׁבַּע הקב"ה שֶׁאֵין הַכִּסֵּא שָׁלֵם וְאֵין הַשֵּׁם מָלֵא עַד שֶׁיִּמַּח שְׁמוֹ שֶׁל עֲמָלֵק בֶּן עֵשָׂו, וּמִשֶּׁנִּמְחָה שְׁמוֹ יְהִי שֵׁם ה' מָלֵא וְהַכִּסֵּא שָׁלֵם, שֶׁנֶּאֱמַר (תהלים ט ז) "הָאוֹיֵב תַּמּוּ חֳרָבוֹת לָנֶצַח", זֶהוּ עֵשָׂו, שֶׁנֶּאֱמַר "וְעֶבְרָתוֹ שְׁמָרָה נֶצַח" (עמוס א יא), "אָבַד זִכְרָם הֵמָּה" (תהלים ט ז), מַה כְּתִיב אַחֲרָיו "וַה' לְעוֹלָם יֵשֵׁב" (שם ח), הֲרֵי הַשֵּׁם מָלֵא, "כּוֹנֵן לַמִּשְׁפָּט כִּסְאוֹ" (שם), הֲרֵי כִּסֵּא שָׁלֵם. לְשׁוֹן רַשִׁ"י (רש"י על שמות י"ז:ט"ז). וּמִדְרַשׁ חֲכָמִים הוּא (תנחומא תצא יא): וְיֵשׁ מְפָרְשִׁים כִּי כַּאֲשֶׁר תִּהְיֶה יָד עַל כִּסֵּא ה' תִּהְיֶה מִלְחָמָה לַה' בַּעֲמָלֵק, וְכֵן תִּהְיֶה מִדּוֹר לְדוֹר. וְהָעִנְיָן, כִּי כַּאֲשֶׁר יִהְיֶה מֶלֶךְ בְּיִשְׂרָאֵל יוֹשֵׁב עַל כִּסֵּא ה' יִלָּחֵם בַּעֲמָלֵק, וְהוּא רֶמֶז לְשָׁאוּל הַמֶּלֶךְ הָרִאשׁוֹן, וְכֵן מִדֹּר דֹּר, לֵאמֹר כִּי כָל מֶלֶךְ בְּיִשְׂרָאֵל חַיָּב לְהִלָּחֵם בָּהֶם עַד שֶׁיִּמָּחוּ. וְגַם זֶה מִדְרַשׁ הַגְּמָרָא שֶׁאָמְרוּ (סנהדרין כ:) כְּשֶׁהוּא אוֹמֵר כִּי יָד עַל כֵּס יָהּ מִלְחָמָה לַה' בַּעֲמָלֵק מִדֹּר דֹּר, הֲרֵי לְהַעֲמִיד עֲלֵיהֶם מֶלֶךְ תְּחִלָּה, וְאֵין "כֵּס יָהּ" אֶלָּא מֶלֶךְ, שֶׁנֶּאֱמַר (דהי"א כט כג) "וַיֵּשֶׁב שְׁלֹמֹה", כִּדְאִיתָא בְּפֶרֶק כֹּהֵן גָּדוֹל (סנהדרין כ:). וְעַל דֶּרֶךְ הַפְּשָׁט נָכוֹן הוּא: וְעַל דֶּרֶךְ הָאֱמֶת, כִּי הַיָּד אֲשֶׁר עַל כִּסֵּא יָהּ, וְהִיא מִלְחָמָה לַה', הוֹיָה בַּעֲמָלֵק מִדֹּר דֹּר, כִּי מִדַּת הַדִּין שֶׁל מַעְלָה תִּהְיֶה בּוֹ לִמְחוֹתוֹ לְעוֹלָם מִדּוֹר דּוֹר. וּמִדְרַשׁ חֲכָמִים (תנחומא תצא טו) בַּשֵּׁם הַמָּלֵא וּבַכִּסֵּא הַשָּׁלֵם יִרְמֹז לָזֶה: וְטַעַם הָעֹנֶשׁ שֶׁנֶּעֱנַשׁ עֲמָלֵק יוֹתֵר מִכָּל הָעַמִּים, בַּעֲבוּר כִּי כָל הָעַמִּים שָׁמְעוּ וַיִּרְגְּזוּן (שמות ט"ו:י"ד), וּפְלֶשֶׁת אֱדוֹם וּמוֹאָב וְיוֹשְׁבֵי כְּנַעַן נָמֹגוּ (שם) מִפְּנֵי פַּחַד ה' וּמֵהֲדַר גְּאוֹנוֹ, וַעֲמָלֵק בָּא מִמֶּרְחָק כְּמִתְגַּבֵּר עַל הַשֵּׁם, וּלְכָךְ אָמַר בּוֹ "וְלֹא יָרֵא אֱלֹהִים" (דברים כה יח), וְעוֹד כִּי הוּא נִין עֵשָׂו וְקָרוֹב לָנוּ, עֹבֵר מִתְעַבֵּר עַל רִיב לֹּא לוֹ:
AND HIS HANDS WERE ‘EMUNAH’. This means that they remained steadily uplifted. The usage of the word is similar to the expressions: ‘va’amanah’ (And a sure) ordinance concerning the singers, as every day required; And yet for all this we make ‘amanah’ (a sure) covenant, meaning a provision “fixed” by covenant. Similarly, a peg fastened in a place ‘ne’eman’ means [sure and] strong. By way of the Truth, [the mystic lore of the Cabala], Moses lifted his ten fingers to the height of heaven in order to allude to the ten emanations and to cleave firmly to Him Who fights for Israel. Here is explained the matter of uplifting of hands during the blessing of the priests, and its secret. FOR THE HAND UPON ‘KEIS Y-AH’ (THE THRONE OF THE ETERNAL). “The hand of the Holy One, blessed be He, is raised to swear by His throne that He will maintain [a state of] war and enmity against Amalek forever. Now what is the significance of the word keis, and why does it not say kisei [as usual]? Furthermore, even the Divine Name is divided into half! [The answer is that] the Holy One, blessed be He, swore that the throne will not be perfect and the Name will not be full until He will blot out the name of Amalek the son of Esau. And when his name will be blotted out, then will G-d’s Name be full and the throne perfect, as it is said, The foe — they are destroyed; perpetual ruins. [This refers to Esau, of whom it is said, And he kept his wrath for ever.] Their very memorial is perished. What is written after that? And the Eternal is enthroned for ever. Thus you see [that after Amalek’s memory has perished], G-d’s Name is full. He hath established ‘kis’o’ (His throne) for judgment. Thus you see that the throne will be perfect.” Thus far the language of Rashi, and it is a Midrash of the Sages. Some scholars explain the verse as meaning that “when there will be a ‘hand,’ [i.e., king, as explained further], upon the throne of the Eternal, the Eternal will have war with Amalek, and so shall it be from generation to generation.” The purport of this is that when there will be a king in Israel sitting upon the throne of the Eternal, he shall wage war against Amalek, thus alluding to Saul, the first king [of Israel]. And so shall it continue from generation to generation, that every king of Israel shall be duty-bound to fight with them until their name will extinct. The following is also a Midrash of the Gemara, as found in [Tractate Sanhedrin] in the chapter of the High Priest: “By saying, The hand upon the throne of the Eternal: the Eternal will have war with Amalek from generation to generation, Scripture intimates that the Israelites must first appoint a king over themselves [before they are to annihilate the offspring of Amalek], for the throne of the Eternal refers only to the king, as it is said, Then Solomon sat on the throne of the Eternal. In line with the plain meaning of Scripture, this is correct. And by way of the Truth, [that is, the mystic lore of the Cabala, the verse is to be understood as meaning] that the Hand, [i.e., the attribute of justice], which is upon the throne of Y-ah, and which is the war from the Eternal, will continue with Amalek from generation to generation, for the high attribute of justice will pursue his extinction forever from generation to generation. The Midrash of the Sages [mentioned above] concerning “the full Divine Name” and “the perfect throne” allude to this [interpretation by way of the Truth]. Now the reason for the punishment of Amalek, i.e., why punitive measures were meted out to him more than to all other nations, is that when all the nations heard [of G-d’s visitation upon the Egyptians], they trembled. Philistia, Edom, and Moab and the inhabitants of Canaan melted away from before the terror of the Eternal, and from the Glory of His majesty, whereas Amalek came from afar as if to make himself master over G-d. It is for this reason that it is said concerning him, and he feared not G-d. Besides, he was a descendant of Esau and related to us, a passer-by who meddles with a quarrel not his own. Yithro