The reference is to the joyous festive meal of the thank offering, in which the Psalmist, restored to health from severe illness and saved from the onslaught of enemies, pays his thanks, feasts in unmingled joy, and bears his testimony of gratitude to his Host for what He has done for him. Such a feast of life the Lord has given us, enough to confound all our skeptical and cynical enemies. We do indeed feel that we are His lifelong guests in His house forever. The Lord's loving care is ours until we die. It was only left for Christ to come on the scene to give us even greater good news that not only could life be mightily fulfilling for those who love the Lord, because He first and always loves us to overflowing, but that that love does not cease with death.
Death is the mere transition to more life, more abundance of love, in other form.
And so this best-loved Psalm is a great story of faith. It is our personal thanksgiving for God's personal love.