Ezra 3:10-11 When the builders laid the foundation of the temple of the Lord, the priests stood in their apparel with trumpets, and the Levites, the sons of Asaph, with cymbals, to praise the Lord, according to the ordinance of David king of Israel. And they sang responsively, praising and giving thanks to the Lord: “For He is good, for His mercy endures forever toward Israel.”
It is estimated the nearly 50,000 people traveled over 900 miles back to Jerusalem with the goal of rebuilding the temple in Jerusalem. This hike may have taken as much as 4 months to make, but they were focused.
So intent of this rebuilding were they that the choir and band were in tune and began to give praises, singing Psalm 136 while the foundation was being built. In the Hebrew it gives the picture that they sang to each other, back and forth with praises.
The mercy they were singing about literally meant in the original “God’s covenant love.” It was God’s love promised or pledged to them.
I heard a report at one time and have recently tried to find it again, that rocks hold sound waves. If this is true, can you just imagine what was happening while the foundation of the temple was being built? Those rocks were being filled with the praises of God’s covenant love. From there they would construct the building.