Moreover, by them is thy servant warned
By whom the psalmist means himself, who was the servant of the Lord, not only in common with other saints, but as he was a king and prophet, and as such he received advantage from the word of God; all his instructions as a prophet, and all his rules of government as a king; and the whole of that wisdom, prudence, and knowledge, with which the conducted in both offices, were from the Lord by his word: and it may be applied to any servant of the Lord, and especially in an ecclesiastical office, as an apostle of Christ, and minister of the word; who serve God in the Gospel of his Son, and, by means of the Scriptures, are furnished for every good work; and also to believers in Christ in common; who, of whatsoever rank and quality, in whatsoever state and condition of life, whether high or low, rich or poor, bond or free, are Christ's servants; and whatsoever is written is for their instruction, and by the word of God they are "warned"; the Scriptures are a way mark to them, to direct them in a right way, and to caution them against turning to the right or left; either to immoral practices, or the errors and heresies of wicked men: it is a lamp to their feet, and a light to their path, and teaches them to walk circumspectly, and warns them of rocks, gins, and snares in the way; or, as the words may be rendered, "by them is thy servant made clear", or "bright" F11; so the word is used in ( Daniel 12:3 ) ; that is, in his understanding: the psalmist confirms, by his own experience, what he had said before of the word, ( Psalms 19:8 ) ; that it enlightened the eyes: the light of the glorious Gospel of Christ shining into the heart gives the light of the glory of God in the person of Christ; it illuminates and irradiates the mind, and gives clear ideas of the glory and perfections of God, of his counsels and covenant, of his works of nature and of grace; and makes a bright discovery of the person, offices, and grace of Christ; and of the blessed Spirit, and his operations; and of the blessings of grace, and of eternal glory and happiness;
[and] in keeping of them [there is] great reward;
which is to be understood, not of keeping the law of Moses, and the precepts of that, which, if a man did keep perfectly and constantly, he should live in them; but of observing the word of God, and by diligent searching into it, reading and learning it, and meditating on it, to get and obtain knowledge of divine things; which carries its own reward with it, and is better than thousands of gold and silver; and of laying up the word of God, and the truths of the Gospel, and keeping them in mind and memory, which is very profitable and serviceable, to promote spiritual peace and comfort, and to preserve from sin, doctrinal and practical; and also of yielding a cheerful obedience to the Gospel, by cordially embracing and professing the doctrines, and submitting to the ordinances of it; from all which arise great profit, and much reward: such come at the knowledge of Jesus Christ, which is preferable to everything else, and is more precious than rubies; and all desirable things; such enjoy the presence of Christ, have much peace and comfort in their souls; they are made wise unto salvation, and are fitted for every good word and work.