Psalms 96:10
Say among the heathen that the LORD reigneth: the world also shall be established that it shall not be moved: he shall judge the people righteously. Say among the heathen that the LORD reigneth: the world also shall be established that it shall not be moved: he shall judge the people righteously.
The charge is to declare among the nations that the Lord is king. That proclamation includes that the ordered world stands firm and cannot be shaken. It includes also that He judges peoples with righteousness. His reign and His judging are set forth as reason for all creation to rejoice, for He comes to judge the earth in righteousness and truth.