Literally he means the Jews mourning in Babylon, but especially the uninterrupted happiness of the church: the Hebrew here for ended signifies recompensed; their days of rejoicing shall abundantly recompense all their days of mourning.
Related Commentaries of Isaiah 60:20
Isaiah 60:20
20 Thy sun shall no more go down; neither shall thy moon withdraw itself: for the LORD shall be thine everlasting light, and the days of thy mourning shall be ended.