Previous oppressors had been nation-states (like Aram-naharaim, Moab, and Canaan). These enemies conquered, occupied and taxed. Their purpose was to ensure a long-term flow of revenue; the goose that lays the golden eggs must be kept alive and fed enough to continue to lay the eggs. Conditions could be harsh but life would go on. Now they confront a horde of barbarians who live in the present and have no thought but of instant gratification. They loot, pillage, and destroy with no thought for the future.
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4 They would encamp against them and devour the produce of the land, as far as Gaza, and leave no sustenance in Israel and no sheep or ox or donkey.