Leviticus 26:23-25 threatens being delivered into enemy hands as covenant curse; Israel's 18-year servitude to Moab fulfills that threat.

Deuteronomy 28:47 directly says you shall serve your enemies for not serving God joyfully; here Israel serves Eglon for 18 years.

Deuteronomy 28:48 continues the curse of serving enemies in hunger and thirst; Israel's servitude under Moab matches this description.