“They did not remember his power or the day when he redeemed them from the foe” (v42). Israel had been rescued from Egypt and from death in the desert, but many still did not trust in God’s saving power. “Despite his wonders, they did not believe” (v32), and this lack of trust caused them to grumble and reject His ways (v10). This psalm urges us not to be like that generation, who were “armed with the bow but turned back on the day of battle” (v9) because they didn’t believe God.
Lack of trust always leads to sin (v10-11). When we have confidence in God’s love and power, we have the courage to obey Him (v7).