Sing, O heavens - In view of the glorious truths stated in the previous verses, that kings should rise up, and princes worship; that the Messiah would be for a light to the Gentiles, and that the true religion would be extended to each of the four quarters of the globe. The idea in this verse is, that it was an occasion on which the heavens and the earth would have cause to exult together. It is common in Isaiah thus to interpose a song of praise on the announcement of any great and glorious truth, and to call on the heavens and the earth to rejoice together (see the notes at Isaiah 12:1-6; Isaiah 42:10-11; Isaiah 44:23).
Related Commentaries of Isaiah 49:13
Isaiah 49:13
13 Sing, O heavens; and be joyful, O earth; and break forth into singing, O mountains: for the LORD hath comforted his people, and will have mercy upon his afflicted.