טו (דברים כ, ח) "מִי הָאִישׁ הַיָּרֵא וְרַךְ הַלֵּבָב" כְּמַשְׁמָעוֹ. שֶׁאֵין בְּלִבּוֹ כֹּחַ לַעֲמֹד בְּקִשְׁרֵי הַמִּלְחָמָה. וּמֵאַחַר שֶׁיִּכָּנֵס בְּקִשְׁרֵי הַמִּלְחָמָה יִשָּׁעֵן עַל מִקְוֵה יִשְׂרָאֵל וּמוֹשִׁיעוֹ בְּעֵת צָרָה וְיֵדַע שֶׁעַל יִחוּד הַשֵּׁם הוּא עוֹשֶׂה מִלְחָמָה וְיָשִׂים נַפְשׁוֹ בְּכַפּוֹ וְלֹא יִירָא וְלֹא יִפְחָד וְלֹא יַחְשֹׁב לֹא בְּאִשְׁתּוֹ וְלֹא בְּבָנָיו אֶלָּא יִמְחֶה זִכְרוֹנָם מִלִּבּוֹ וְיִפָּנֶה מִכָּל דָּבָר לַמִּלְחָמָה. וְכָל הַמַּתְחִיל לַחְשֹׁב וּלְהַרְהֵר בַּמִּלְחָמָה וּמַבְהִיל עַצְמוֹ עוֹבֵר בְּלֹא תַּעֲשֶׂה. שֶׁנֶּאֱמַר (דברים כ, ג) "אַל יֵרַךְ לְבַבְכֶם אַל תִּירְאוּ וְאַל תַּחְפְּזוּ וְאַל תַּעַרְצוּ מִפְּנֵיהֶם". וְלֹא עוֹד אֶלָּא שֶׁכָּל דְּמֵי יִשְׂרָאֵל תְּלוּיִין בְּצַוָּארוֹ. וְאִם לֹא נִצֵּחַ וְלֹא עָשָׂה מִלְחָמָה בְּכָל לִבּוֹ וּבְכָל נַפְשׁוֹ. הֲרֵי זֶה כְּמִי שֶׁשָּׁפַךְ דְּמֵי הַכּל. שֶׁנֶּאֱמַר (דברים כ, ח) "וְלֹא יִמַּס אֶת לְבַב אֶחָיו כִּלְבָבוֹ". וַהֲרֵי מְפֹרָשׁ בַּקַּבָּלָה (ירמיה מח, י) "אָרוּר עשֶֹׁה מְלֶאכֶת ה' רְמִיָּה" וְאָרוּר מֹנֵעַ חַרְבּוֹ מִדָּם. וְכָל הַנִּלְחָם בְּכָל לִבּוֹ בְּלֹא פַּחַד וְתִהְיֶה כַּוָּנָתוֹ לְקַדֵּשׁ אֶת הַשֵּׁם בִּלְבַד. מֻבְטָח לוֹ שֶׁלֹּא יִמְצָא נֵזֶק וְלֹא תַּגִּיעֵהוּ רָעָה. וְיִבְנֶה לוֹ בַּיִת נָכוֹן בְּיִשְׂרָאֵל וְיִזְכֶּה לוֹ וּלְבָנָיו עַד עוֹלָם וְיִזְכֶּה לְחַיֵּי הָעוֹלָם הַבָּא. שֶׁנֶּאֱמַר (שמואל א כה, כח) "כִּי עָשֹׂה יַעֲשֶׂה ה' לַאדֹנִי בַּיִת נֶאֱמָן כִּי מִלְחֲמוֹת ה' אֲדֹנִי נִלְחָם וְרָעָה לֹא תִמָּצֵא בְךָ" וְגוֹ' (שמואל א כה, כט) "וְהָיְתָה נֶפֶשׁ אֲדֹנִי צְרוּרָה בִּצְרוֹר הַחַיִּים אֵת ה' אֱלֹהֶיךָ":
15 "What man is there who is fearful and is faint-hearted" (Deut. 20:8)? Exactly so. This is one whose heart has no strength to withstand the strains of war. Now, once one becomes entangled with the perplexities of war, he should trust the Hope of Israel, and He will save him in times of trouble. He should know he is doing battle for the unity of the Name. He should place his life in His Hands and neither be afraid nor alarmed. He should not think about his wife or his children. Rather, he should wipe away thoughts of them from his heart, and clear himself of everything for the war. Anyone who thinks about or contemplates (matters) during the battle and frightens himself violates a Negative Commandment, as it says, “ do not be faint of heart, nor be alarmed, do not flee, and be not frightened before them ” (Deut. 20:3). And not only that, but all the blood of Israel hangs around his neck. If he did not win and did not fight the battle with all his heart and soul, he is like one who spills everyone’s blood, as it says, “ lest he not melt his brothers’ hearts as has his ” (Deut. 20:8). It is explicitly stated in the Tradition that, “ Cursed be he who does the work of G-d sluggishly, and cursed be he who keeps back his sword from blood ” (Jeremiah 48:10). However, anyone who does fight with all his heart without fear, and his intentions are only to Sanctify the Name, is promised that he will not be harmed and nothing bad will happen to him. He will build an upright home in Israel, and he and his children will earn merit forever, and merit The World To Come, as it says, “ certainly, G-d shall make for my master a faithful house, for the wars of G-d does my master fight and no evil will be found with you all your days…And the soul of my master will be bound with the living, with the Lord your G-d… ” (I Samuel 25:28-29).