Charles Ellicott Commentary Isaiah 52:8

"The voice of thy watchmen! they lift up the voice, together do they sing; for they shall see eye to eye, when Jehovah returneth to Zion." — Isaiah 52:8 (ASV)

Thy watchmen ... —The sentinels see the heralds from their watch-towers (Isaiah 21:6; Habakkuk 2:1), and sing out for joy, as they see, not only from far off, but eye to eye, the presence of the God who has become the King.