A true relationship with God relies on inner sincerity rather than empty outward declarations. The primary approach among commentators highlights a deep contradiction between what the Israelites said and what they actually thought. On the surface, they spoke with loyalty and faith, but their hearts did not match their words [רש״י, ביאור שטיינזלץ, מצודת דוד]. They operated under the false belief that God was unaware of their hidden thoughts, assuming they could deceive Him through mere lip service [מלבי״ם].
This negative behavior teaches a fundamental lesson about serving God: the foundation of all prayer is the genuine intention of the heart, not just the physical words spoken [אבן עזרא]. Looking back at the generation that wandered the wilderness, this pattern becomes clear. Even when the people admitted their wrongs or acknowledged God as their foundation, their actions lacked true, wholehearted repentance [אלשיך]. Yet, despite their deep insincerity and their failure to remain faithful to His covenant, God responded with compassion. He chose to forgive their wrongdoings and held back from destroying them completely [רש״י].