Thomas Aquinas Commentary Jeremiah 33:10-11

"Thus saith Jehovah: Yet again there shall be heard in this place, whereof ye say, It is waste, without man and without beast, even in the cities of Judah, and in the streets of Jerusalem, that are desolate, without man and without inhabitant and without beast, the voice of joy and the voice of gladness, the voice of the bridegroom and the voice of the bride, the voice of them that say, Give thanks to Jehovah of hosts, for Jehovah is good, for his lovingkindness [endureth] for ever; [and of them] that bring [sacrifices of] thanksgiving into the house of Jehovah. For I will cause the captivity of the land to return as at the first, saith Jehovah." — Jeremiah 33:10-11 (ASV)

Here, he promises their happiness:

1. Temporal joy: the voice of joy. As mentioned previously: I will destroy from them the voice of joy and the voice of gladness, the voice of the groom and the voice of the bride, the sound of the millstone and the light of the lamp (Jeremiah 25:10).
2. Spiritual joy expressed with divine praises: the voice of those who say: give thanks to the LORD. Joy and gladness shall be found in her, thanksgiving, and the voice of praise (Isaiah 51:3). Alleluia shall be sung throughout all her streets . This joy is also expressed with offerings: and of those that bring their vows into the house of the LORD. They shall worship him with sacrifices and gifts, and they shall swear vows to the Lord, and fulfill them (Isaiah 19:21).
3. He gives the reason: for I will bring back the captivity of the land. Renew our days as from the beginning (Lamentations 5:21).