They sang to one another in praising and giving thanks to Yahweh, “For he is good, for his loving kindness endures forever toward Israel.” All the people shouted with a great shout, when they praised Yahweh, because the foundation of Yahweh’s house had been laid.
Ezra 3:9 Then Jeshua stood with his sons and his brothers, Kadmiel and his sons, the sons of Judah, together, to have the oversight of the workmen in God’s house: the sons of Henadad, with their sons and their brothers the Levites.
Ezra 3:10 When the builders laid the foundation of Yahweh’s temple, they set the priests in their clothing with trumpets, with the Levites the sons of Asaph with cymbals, to praise Yahweh, according to the directions of David king of Israel.
Ezra 3:11 They sang to one another in praising and giving thanks to Yahweh, “For he is good, for his loving kindness endures forever toward Israel.” All the people shouted with a great shout, when they praised Yahweh, because the foundation of Yahweh’s house had been laid.
Ezra 3:12 But many of the priests and Levites and heads of fathers’ households, the old men who had seen the first house, when the foundation of this house was laid before their eyes, wept with a loud voice. Many also shouted aloud for joy,
Ezra 3:13 so that the people could not discern the noise of the shout of joy from the noise of the weeping of the people; for the people shouted with a loud shout, and the noise was heard far away.
The verse centers on "sang", "another", "praising", "giving", "thanks", "yahweh", "good", and "loving". It is saying that the verse draws attention to "sang" and "another", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "When the builders laid the foundation of..." into verse 12's "But many of the priests and Levites...", so "sang" and "another" belong inside that flow. In Ezra context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "sang" and "another" with trust shaped by these words, not by a vague optimism outside the passage.