Deuteronomy 23:6

Ver. 6. Thou shalt not seek their peace— All that is here forbidden is, the entering into public confederacies and alliances with them; notwithstanding which prohibition, they were bound to treat those people according to the rule of common justice and humanity. The words may be considered as a declaration of the inflexible resolution of these two nations to maintain idolatry, and to keep up the same hostile spirit towards the Hebrews, which their ancestors had begun; otherwise, if they had publicly renounced their idolatry, and courted the favour of the Israelites, this law would have been abrogated of course, the reasons for which it was made then ceasing.