Deuteronomy 23:6
Thou shalt not seek their peace nor their prosperity all thy days for ever.
Cross-reference
2 Samuel 8:2
Historical context
2 Samuel 8:2 describes David's conquest of Moab, carrying out the perpetual hostility commanded in Deuteronomy 23:6.
Ezra 9:12
Citation
In Ezra 9:12, the same command not to seek peace or prosperity for Ammonites and Moabites is reiterated when dealing with foreign marriages.
Nehemiah 13:23–25
Historical context
In Nehemiah 13:23-25, this prohibition is enforced against Jews who married Ammonite and Moabite women.
Matthew 5:43
Citation
Matthew 5:43 quotes a tradition that twists this command into 'hate your enemy', which Jesus contrasts with loving enemies.