Charles Ellicott Commentary Isaiah 49:13

"Sing, O heavens; and be joyful, O earth; and break forth into singing, O mountains: for Jehovah hath comforted his people, and will have compassion upon his afflicted." — Isaiah 49:13 (ASV)

Sing, O heavens. —As in Isaiah 44:23, all nature is invited to join in the chorus of praise for the deliverance of Israel.