Isaiah 51:11

“Therefore the redeemed of the Lord shall return, &c.] Or “and”, or “so”f1011. In like manner, and as sure as the Israelites had a way made for them through the sea to pass over, so sure shall all those that are redeemed by the blood of Christ from sin, Satan, the law, death, and hell, be gathered out of the nations of the world, and from the antichristian states, and shall be converted and turn to the Lord. Or these words are a continuation of the above prayer, as Jarchi, “let them return”; or rather are an answer to it, and a promise that they should: and come with singing unto Zion; to the Gospel church, and join themselves to it, praising God for his grace in calling and converting them,…”

“(Isa 35:10). Therefore--assurance of faith; or else the answer of Jehovah corresponding to their prayer. As surely as God redeemed Israel out of Egypt, He shall redeem them from Babylon, both the literal in the age following, and mystical in the last ages (Rev 18:20-21). There shall be a second exodus (Isa 11:11-16; Isa 27:12-13). singing--image from the custom of singing on a journey when a caravan is passing along the extended plains in the East. everlasting joy-- (Jde 1:24). sorrow . . . flee away-- (Rev 21:4).”

“Therefore the redeemed of the Lord - This is probably the language of Yahweh assuring them, in answer to their prayer, that his ransomed people should again return to Zion. And everlasting joy shall be upon their head - This entire verse occurs also in Isaiah 35:10. See it explained in the note on that verse. The custom of singing alluded to here on a journey is now very common in the East. It is practiced to relieve the tediousness of a journey over extended plains, as well as to induce the camels in a caravan to move with greater rapidity. The idea here is, that the caravan that should return from Babylon to Jerusalem, across the extended plains, should make the journey amidst general…”

“Therefore - This verse contains an answer to the prophet's prayer. I did these great things, and I will do the like again. Joy - Like a crown of glory. Isaiah 51:13”

“the redeemed: Isa 35:10, Isa 44:23, Isa 48:20, Isa 49:13; Jer 30:18, Jer 30:19, Jer 31:11, Jer 31:12, Jer 33:11; Act 2:41-47; Rev 5:9-13, Rev 7:9, Rev 7:10, Rev 14:1-4, Rev 19:1-7 everlasting: Isa 60:19, Isa 61:7; Co2 4:17, Co2 4:18; Th2 2:16; Jde 1:24 and sorrow: Isa 25:8, Isa 60:20, Isa 65:19; Rev 7:17, Rev 21:1, Rev 21:4, Rev 22:3 Isaiah 51:12”