"Do not harden your hearts as you did at Meribah …” (v8). The psalmist urged God’s people to worship and trust Him as the Good Shepherd (v7), rather than “hardening your hearts” and turning to idols. The generation of Israelites that had been rescued from Egypt refused to trust God, despite His miracles for them, and so they died in the wilderness and missed out on the Promised Land (v9-11). They turned away from “the Rock of our salvation” (v1).
“We are the people of His pasture” (v7). The false idols of sin will destroy our souls, but our Good Shepherd lays down his life to save us.