Charles Ellicott Commentary Isaiah 54:1

"Sing, O barren, thou that didst not bear; break forth into singing, and cry aloud, thou that didst not travail with child: for more are the children of the desolate than the children of the married wife, saith Jehovah." — Isaiah 54:1 (ASV)

Sing, O barren ... —The words seem to carry on the jubilant strain of Isaiah 51:0, Isaiah 52:1–12, leaving the section Isaiah 52:13 to Isaiah 53:12, as a mysterious episode, inserted, it may be, by the prophet to show how the restoration of Israel and the victory of righteousness had become possible. We note, as bearing on Isaiah’s studies, the parallelism with 1 Samuel 2:5. The “children of the desolate” are primarily the returning exiles, ultimately all the citizens of the heavenly Jerusalem.