Psalms 48:11

Let mount Zion rejoice, let the daughters of Judah be glad, because of thy judgments.

The call for Zion to rejoice and for the daughters of Judah to be glad rests on the fact that divine judgments had brought them deliverance from their enemies. That gladness was not summoned in the abstract but followed a concrete rescue in which hostile powers were overthrown by God's intervening judgment. It came after the people had trusted wholly in God rather than in their own strength, and had thereby proved Him to be their fortress and deliverer. Having thus experienced His saving action, they were able to praise Him with understanding for the righteousness of His judgments.