In 1 Chronicles 15, King David brings the ark up to Jerusalem, to set it on Mount Zion. You will see that there was to be singing as the ark was carried forward and up the hill. This Psalm gives us the words of the song which they sang long ago. But, amazing to realize, this same song shall be sung in a future day by the believing remnant of Jews.
V.15 They have come within sight of Mount Zion and they are filled with praise. This may be hard to understand. They describe what was happening in King David’s day; but they also are telling what Israel can expect when the Lord Jesus returns to reign over the earth as King during the millennium (1,000 years).
V.19 They cannot take any glory to themselves, but bless the Lord for His daily blessings and for His goodness in restoring them to their land.