1-3 Intro; 4-9 Satisfaction in the LORD; 10-16 Salvation thru; 17-22 Sacrifices to; 23-32 Sovereignty of; 33-38 Sustenance by; 39-43 Support thru
This strophe (17-22) is addressed to those who had been sick & near death but the LORD saved them. It is these people who are exhorted to thank the LORD for having saved them.
Who- “let the redeemed of the LORD say so”
What- “give thanks” to express gratitude or show appreciation to someone
Why - “for his lovingkindness and for his wonders”