Thy righteousness is an everlasting righteousness. Here the law of God is honored by the additional encomium, that it is everlasting righteousness and truth; as if it had been said, that all other rules of life, with whatever attractions they may appear to be recommended, are but a shadow, which quickly vanishes away. The Psalmist, no doubt, indirectly contrasts the doctrine of the law with all the human precepts which were ever delivered, that he may bring all the faithful in subjection to it, since it is the school of perfect wisdom. There may be more of plausibility in the refined and subtle disquisition's of men; but there is in them nothing firm or solid at bottom, as there is in God's law. This firmness of the divine law he proves in the following verse from one instance -- the continual comfort he found in it when grievously harassed with temptations. And the true test of the profit we have reaped from it is, when we oppose to all the distresses of whatever kind which may straiten us, the consolation derived from the word of God, that thereby all sadness may be effaced from our minds. David here expresses something more than he did in the preceding verse; for there he only said that he reverently served God, although from his rough and hard treatment he might seem to lose his labor; but now when distressed and tormented, he affirms that he finds in the law of God the most soothing delight, which mitigates all grief's, and not only tempers their bitterness, but also seasons them with a certain sweetness. And assuredly when this taste does not exist to afford us delight, nothing is more natural than for us to be swallowed up of sorrow. Nor ought we to omit noticing the form of expression which the Prophet employs, by which he teaches, that although he was besieged and shut up on all sides, he found a remedy sufficiently powerful in improving the consolation offered him by the word of God. As this could not be true of the bare commandments, which so far from remedying our distresses, rather fill us with anxiety, there is no doubt that under the word commandments there is comprehended by the figure synecdoche, the whole doctrine of the law, in which God not only requires what is right, but in which also calling his elect ones to the hope of eternal salvation, he opens the gate of perfect happiness. Yea, under the term law are comprehended both free adoption, and also the promises which flow from it.

Thy righteousness is an everlasting righteousness - It never changes. The principles of thy law, of thy government, and of thy method of saving people, are the same under all dispensations, in every land, in all worlds; and they will remain the same forever. Human governments change. Old dynasties pass away. New laws are enacted under new administrations. Customs change. Opinions change. People change. The world changes. But as God himself never changes, so it is with his law. That law is founded on eternal truth, and can never change.
And thy law is the truth - It is founded on "truth;" on the reality of things. It is so essentially founded on truth, it springs so certainly out of truth, or out of the reality of things, that it may be said to be the truth itself. He who understands the law of God understands what truth is, for it is the expression and the exponent of that which is true.

Thy righteousness is an everlasting righteousness - The word צדק tsedek is a word of very extensive meaning in the Bible. It signifies, not only God's inherent righteousness and perfection of nature, but also his method of treating others; his plan of redemption; his method of saving others. And the word δικαιοσυνη, which answers to it, in the Septuagint and in the New Testament, is used with the same latitude of meaning, and in the same sense; particularly in that remarkable passage, Romans 3:25-26 (note), where see the notes. Thy merciful method of dealing with sinners and justifying the ungodly will last as long as the earth lasts; and thy law that witnesses this, in all its pages, is the truth.

Thy righteousness is an everlasting righteousness,.... Or, "is for ever" (z). The rectitude of his nature, his faithfulness in his promises, and his kindness and beneficence to his people; and particularly the righteousness of God revealed in the Gospel; the righteousness of his Son, which he approves and accepts of, and imputes to him that believes. This is a righteousness that will last for ever, will never be abolished; it will answer for them that have it in a time to come; it is of use throughout the whole of life, at death, in the day of judgment, and to all eternity; see Daniel 9:24;
and thy law is the truth; or "thy doctrine"; or "thy word", as the Arabic version. The Scriptures are called the Scriptures of truth, Daniel 10:21 they come from the God of truth, and all that is contained in them is truth; the legal part of them is truth, and so is the Gospel; that is called the word of truth, and truth itself: it is concerning Christ, who is the truth; and it is directed into and made effectual by the Spirit of truth, and contains in it many excellent truths; and is therefore deservedly valued and esteemed by all good men; see John 17:17.
(z) "in seculum", Pagninus, Montanus, Gejerus; "in aeternum", V. L. Michaelis.

The principles of God's government are permanent and reliable, and in the deepest distress His people find them a theme of delightful meditation and a source of reviving power (Psalm 119:17, Psalm 119:116).
law is the truth--It therefore cannot deceive as to its promises.
everlasting-- (Psalm 111:3), though to outward appearance seeming dead.

Everlasting - The same in all ages and places.