I. What he will do for the church. A prophet, as he is a seer, so he is a spokesman. This prophet resolves to perform that office faithfully, v. 1. He will not hold his peace; he will not rest; he will mind his business, will take pains, and never desire to take his ease; and herein he was a type of Christ, who was indefatigable in executing the office of a prophet and made it his meat and drink till he had finished his work. Observe here, 1. What the prophet's resolution is: He will not hold his peace. He will continue instant in preaching, will not only faithfully deliver, but frequently repeat, the messages he has received from the Lord. If people receive not the precepts and promises at first, he will inculcate them and give them line upon line. And he will continue instant in prayer; he will never hold his peace at the throne of grace till he has prevailed with God for the mercies promised; he will give himself to prayer and to the ministry of the word, as Christ's ministers must (Acts vi. 4), who must labour frequently in both and never be weary of this well-doing. The business of ministers is to speak from God to his people and to God for his people; and in neither of these must they be silent. 2. What is the principle of this resolution—for Zion's sake, and for Jerusalem's, not for the sake of any private interest of his own, but for the church's sake, because he has an affection and concern for Zion, and it lies near his heart. Whatever becomes of his own house and family, he desires to see the good of Jerusalem and resolves to seek it all the days of his life, Ps. cxxii. 8, 9; cxviii. 5. It is God's Zion and his Jerusalem, and it is therefore dear to him, because it is so to God and because God's glory is interested in its prosperity. 3. How long he resolves to continue this importunity—till the promise of the church's righteousness and salvation, given in the foregoing chapter, be accomplished. Isaiah will not himself live to see the release of the captives out of Babylon, much less the bringing in of the gospel, in which grace reigns through righteousness unto life and salvation; yet he will not hold his peace till these be accomplished, even the utmost of them, because his prophecies will continue speaking of these things, and there shall in every age be a remnant that shall continue to pray for them, as successors to him, till the promises be performed, and so the prayers answered that were grounded upon them. Then the church's righteousness and salvation will go forth as brightness, and as a lamp that burns, so plainly that it will carry its own evidence along with it. It will bring honour and comfort to the church, which will hereupon both look pleasant and appear illustrious; and it will bring instruction and direction to the world, a light not only to the eyes but to the feet, and to the paths of those who before sat in darkness and in the shadow of death.