Comentario sobre Deuteronómio 20:4

כי ה׳ אלהיכם וגו׳ FOR THE LORD YOUR GOD [IS HE WHO GOETH WITH YOU] — They come to war relying on the conquering strength of human beings (lit., flesh and blood) but you come relying on the strength of the Omnipresent God! The Philistines once came to war relying on the strength of Goliath — what was his end? He fell and they fell with him (Sotah 42a).

כי ה' אלוקיכם ההולך עמכם, “for the Lord your G’d is the One going with you.” The details about who is subject to the draft are meant to remind us that in spite of our feeling physically superior to our enemies, success in war, as in other enterprises that are facing opposition, depends on G’d’s being on our side. If He is, we will win, if not, our numerical superiority or our superior weaponry will not secure us victory either.

להושיע אתכם, “to save you.” This promise refers to total salvation, i.e. that the Israelites would not suffer casualties in their war of conquest against the seven Canaanite nations. It will be just like the punitive campaign against Midian when not a single Israelite soldier was even hurt (Numbers 31,49). It is customary that even victorious armies sustain many casualtis in battle. A war fought as a divine commandment is one when the people carrying out the commandments will prove immune. This is why Joshua was so upset when in the first battle of Ai his army sustained 36 casualties (Joshua 7,5-7). Actually, according to a commentary in Sanhedrin 44, the “36” casualties were merely a single soldier named Yair ben Menashe, who was such an outstanding person that he was considered as equivalent to 36 members of the 71-member Sanhedrin.

This refers to the camp of the sacred ark. Because it is impossible to say that it refers to the Holy One Blessed Is He that He marches with you, since the whole world is full of His glory. Therefore he explains, “This refers to the camp, etc.”

להלחם לכם..להושיע אתכם, "to do battle for you with your enemies and to save you." The meaning of להלחם is to destroy your enemies, whereas the additional להושיע אתכם means to ensure that not one of you becomes a casualty of war. This last point is always the essence of the miracle by means of which we know that G'd fights on our side. This may be the reason that at the beginning of the verse the Torah mentions ה׳ אלוקיכם emphasising that both the attribute of Mercy and the attribute of Justice are involved here. The attribute of Mercy expresses itself by saving the Israelites, the attribute of Justice by destroying its adversaries. Had it not been for the Torah wanting to emphasise this it only had to write כי אלוקיכם הולך.

ההלך עמכם [FOR THE LORD THY GOD] GOETH WITH THEE — this refers to the camp of the Holy Ark (the camp that has the Holy Ark in its midst, i.e. the camp of the Levites) (Sotah 42a).

להושיע אתכם, “to save you.” Moses adds these words even though he had already told the people that G’d would participate as a Warrior on their side. The reason is that even victory in war does not mean that the winning side does not sustain casualties, sometimes very heavy casualties. Moses assures the people that in justified wars G’d would ensure that they would not sustain such casualties. A priest, who is a servant of Hashem, warns the assembled soldiers to be G’d-fearing, and to be confident of His help. The שוטרים, the enforcers of the law, are concerned with the more mundane aspects of warfare, the fact that people worry about their lives when exposed to abnormal dangers. He concentrates on three major concerns of such young soldiers, the betrothed, the ones engaged in building a house, and the ones who just began to establish an economic base for themselves, by planting a vineyard, but not having tasted any of its fruit. These three groups of young men are sent home before the battle is joined.