This place name appears in Isaiah 28:21 as 'Mount Perazim,' referencing a location where God previously intervened in battle. The name means 'breaches' or 'breakings forth,' likely referring to Baal-perazim where David defeated the Philistines (2 Samuel 5:20). There David said, 'The LORD has broken through my enemies before me like a breaking flood,' giving the place its name. Isaiah invokes this memory ironically: as God once broke through David's enemies, now He will rise up to do His 'strange work' and perform His 'alien deed'—fighting against His own people Judah. The geographical reference emphasizes the reversal: covenant blessing becomes covenant curse.