This psalm is an assertion of the covenant God has made with David, and a reminder that this covenant is unconditional, "Forever I will keep my steadfast love for him, and my covenant with him will stand firm" (23).
Reading this psalm after the exile, the Jews could adopt God's promise to David as king to themselves as descendants of the people in David's kingdom. Christians have also appropriated this promise since we recognize Jesus as a direct descendant of David.
We might discuss who is included and if anyone is not.
And we need to think about what this unconditional covenant means.
Verses 30-33 remind us that sin has consequences. We may suffer because of wrong choices we have made. We may suffer because of wrong choices someone else has made.
Sin has consequences.
Yet, God doesn't give up on us so easily.
We need to remember both of those things.