“Assail the Midianites” – although I wrote: “When you approach a city to wage war against it, you shall call to it for peace” (Deuteronomy 20:10), to these you shall not do so; “you shall not seek their peace or their welfare” (Deuteronomy 23:7).8The verse refers to Moav and Amon. You find regarding one who approached them with the attribute of mercy, ultimately he came to scorn, wars, and assailing.
Who was that? It was David. “David said: I will act with kindness to Ḥanun son of Naḥash” (II Samuel 10:2). The Holy One blessed be He said to him: ‘Will you violate my directive?
I wrote: “You shall not seek their peace or their welfare,” and you perform acts of kindness with them? “Do not be overly righteous” (Ecclesiastes 7:16) – so that a person will not relinquish the Torah. But this one sends to comfort the children of Amon and to perform kindness with them.’ Ultimately, he came to scorn: “Ḥanun took David’s servants, and he shaved half their beards, and he cut their garments in half, until their buttocks, and he sent them away” (II Samuel 10:4).
And he came to war with Aram Naharayim, the kings of Tzova, the kings of Maakha, and with the children of Amon, four nations. And it is written: “Yoav saw that the face of the battle was [before and behind him]” (II Samuel 10:9). Who caused this to David? It is because he sought the welfare of those in whose regard the Holy One blessed be He said: “You shall not seek their peace [or their welfare].” That is why it is written: “Assail the…”