Let mount Zion rejoice - Let Jerusalem, the holy city, rejoice or be glad. Mount Zion is evidently used here to designate the city; and the idea is, that the city of God - the holy city - had occasion for joy and gladness in view of the manifestation of the divine favor.
Let the daughters of Judah be glad - The phrase “daughters of Judah” “may” denote the smaller cities in the tribe of Judah, that surrounded Jerusalem as the “mother” city - in accordance with an usage quite common in the Hebrew Scriptures. See the notes at Isaiah 1:8. Perhaps, however, the more obvious interpretation is the correct one, as meaning that the women of Judah had special occasion to rejoice on account of their deliverance from so great danger, and from the horrors which usually attended the siege or the conquest of the city - the atrocities which commonly befall the female sex when a city is captured in war. The “daughters of Judah” are those descended from Judah, or connected with the tribe of Judah. Jerusalem was in the bounds of that tribe, and the name Judah was given to all those that remained after the removal of the ten tribes.
Because of thy judgments - Thy righteous interposition in delivering the city and people.