Isaiah 52:9

Break forth into joy, sing together, ye waste places of Jerusalem,.... This is what the watchmen shall say when they lift up their voice; this will be one part of their song, and the intent of it; to observe to the members of the churches, which shall be constituted in those parts which were formerly barren and desolate, what wonderful things the Lord has done in bringing again Zion; in building up the ruins of it; in the clear light of the Gospel he has caused to break forth, and in the good tidings of peace and salvation published; on account of all which they are called upon to express the greatest joy in a social manner, with the utmost unanimity, as having everyone a concern therein:

for the Lord hath comforted his people; with his divine presence, and the light of his countenance; with the discoveries of his love; with the joys of his salvation by Christ; with the comforts of his Spirit; with the doctrines of the Gospel, and the exceeding great and precious promises of it; with the ordinances of his house, those breasts of consolation; and by enlarging his kingdom and interest with the conversion of Jews and Gentiles; and particularly by the donation and application of the various blessings of grace through Christ, and especially that which follows:

he hath redeemed Jerusalem; the same with his people, particularly the Jews, now converted; who will have the blessing of redemption, obtained by the Messiah, made known and applied unto them; which will be matter of comfort to them: as it is to all sensible sinners, who see themselves lost and undone; liable to the wrath of God, and curses of the law; under a sentence of condemnation; the captives of sin and Satan, and prisoners of law and justice; unable to redeem themselves, or any creature capable of giving a ransom for them.