Charles Ellicott Commentary Isaiah 42:10

"Sing unto Jehovah a new song, and his praise from the end of the earth; ye that go down to the sea, and all that is therein, the isles, and the inhabitants thereof." — Isaiah 42:10 (ASV)

Sing to the Lord a new song. —These words are familiar in the Psalms (Psalms 33:3; Psalms 40:3; Psalms 98:1) and are probably quoted from them.

The only touch of definite localization is found in the mention of Kedar (See Note on Isaiah 21:16). Starting from this, the other terms gain a more defined significance. The proclamation seems to be addressed to the nations of the Eastern, not the Western world, as if to the ships that sailed from Elath or Ezion-geber down the Elanitic Gulf.

The rock, or Sela , is the Petra of Roman Idumea; the ships are those that trade to Ophir or the land of Sinim. The cities and the nomad tribes are all invited to join in the hymn of praise, and it is to be echoed in the far-off “islands,” or coasts, of the Indian Ocean.