The voyce of ioy and the voyce of gladnes, the voyce of the bridegrome, and the voyce of the bride, the voyce of them that shall say, Prayse the Lord of hostes, because the Lord is good: for his mercy endureth for euer, and of them that offer the sacrifice of prayse in the House of the Lord, for I will cause to returne the captiuitie of the land, as at the first, sayth the Lord.
Jeremiah 33:9 And it shalbe to me a name, a ioy, a praise, and an honour before all the nations of the earth, which shall heare all ye good that I doe vnto them: and they shall feare and tremble for all the goodnes, and for all the wealth, that I shew vnto this citie.
Jeremiah 33:10 Thus sayth the Lord, Againe there shalbe heard in this place (which ye say shalbe desolate, without man, and without beast, euen in the cities of Iudah, and in the streetes of Ierusalem, that are desolate without man, and without inhabitant, and without beast)
Jeremiah 33:11 The voyce of ioy and the voyce of gladnes, the voyce of the bridegrome, and the voyce of the bride, the voyce of them that shall say, Prayse the Lord of hostes, because the Lord is good: for his mercy endureth for euer, and of them that offer the sacrifice of prayse in the House of the Lord, for I will cause to returne the captiuitie of the land, as at the first, sayth the Lord.
Jeremiah 33:12 Thus sayth the Lord of hostes, Againe in this place, which is desolate, without man, and without beast, and in all the cities thereof there shall be dwelling for shepheards to rest their flockes.
Jeremiah 33:13 In the cities of the mountaines, in the cities in the plaine, and in the cities of the South, and in the land of Beniamin, and about Ierusalem, and in the cities of Iudah shall the sheepe passe againe, vnder the hand of him that telleth them, sayth the Lord.
The verse centers on "mercy", "voyce", "gladnes", and "bridegrome". It is saying that the verse draws attention to "mercy" and "voyce", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "Thus sayth the Lord Againe there shalbe..." into verse 12's "Thus sayth the Lord of hostes Againe...", so "mercy" and "voyce" belong inside that flow. In Jeremiah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "mercy" and "voyce" with trust shaped by these words, not by a vague optimism outside the passage.