Jeremiah 31:13
Then shall the virgin rejoice in the dance, both young men and old together: for I will turn their mourning into joy, and will comfort them, and make them rejoice from their sorrow. Then shall the virgin rejoice in the dance, both young men and old together: for I will turn their mourning into joy, and will comfort them, and make them rejoice from their sorrow.
The verse belongs to the prophecy of Israel's restoration after exile, in which God would gather and redeem His people and bring the return of the captives, studied as a sure promise. It promises that He will turn mourning into joy, comfort the sorrowful, and make them rejoice from their sorrow, with young men and old rejoicing together. That restoration shows that His chastisement of His people was meant for their good and not for their destruction. The promise stands with the same chapter's assurance of His renewed relationship with His people, His forgiveness, and His law written in their hearts.
It applies to those who mourn over their sins, whose sorrow is turned into joy and given reason to rejoice when they ask God for pardon and are freely forgiven. It also shows His care for the meek and humble, who are precious in His sight despite the world's scorn. In times of trial and grief His ways may seem dark to human understanding, but they are merciful and lead to salvation, since affliction can reveal faults so that people may overcome them by His grace.