You shall not seek their peace nor their prosperity all your days forever.
All Commentaries on Deuteronomy 23:6 Go To Deuteronomy 23
George Leo Haydock
Peace. Hebrew, "ask or seek not their peace nor their advantage "as a nation; keep at a proper distance; have no familiarity with them. (Haydock)
Their vices, not their persons, are to be hated. David behaved in a friendly manner with the king of Ammon, 2 Kings x. 2. He was afterwards forced to make war upon the people, though, without such extraordinary provocations, war was not to be declared against them. (Calmet)
Prosperity. Have no intercourse with them. (Menochius)
Septuagint, "Salute them not, wishing them what may tend to their peace and advantage."