Commentators stress that Ephraim's (Israel's) sin wasn't just occasional lying, but an entire religious system that "encompassed" God with falsehood. Scholars like Albert Barnes and John Calvin explain that half-hearted worship, insincere prayers, and repentance for show are not merely imperfect; God sees them as complete deceit. All half-belief is unbelief, and God cannot be fooled by outward appearances when the heart is far from Him.