This beautiful call and response recounts God's provision to His people. What possible response could there be but "His love endures forever"?
Years ago, while traveling in the Holy Land our leader led us in this Psalm while we took communion in the moonlight by the Dead Sea.
And he told us that in many Jewish households on that night -- it was Passover -- this Psalm would be recited, as Passover is a season of remembering God's faithfulness. But, in many of those households, the response would be changed to reflect the faithlessness of God's people: "We would have thought it sufficient."
Each individual provision of God's should have been sufficient to prompt our undying faithfulness. Yet we rebel and grumble and moan and whine and complain. Again and again.
And again and again, God shows His mercy, His compassion, His love for His own.