John Gill's Exposition of the Whole Bible
Psalms 18:26
With the pure thou wilt show thyself pure,.... None of Adam's posterity are pure by nature; they are all defiled with sin; and though some are pure in their own eyes, they are far from being cleansed from their filthiness; such only are pure who are sanctified by the Spirit of God, have clean hearts created in them, and whose hearts are purified by faith in the blood of Christ; who are justified by Christ's righteousness, and are washed from their sins in his blood; and who, in consequence of such grace, love, pureness of heart, speak a pure language, hold the mystery of faith in a pure conscience, and with a pure conversation, and live soberly, righteously, and godly: and whereas God is a pure and holy Being, his perfections, works, and word, are pure; he shows himself to be so to such persons, by providing for the honour of his purity and holiness in their redemption, sanctification, and salvation; by making all things to be pure to them; by granting them his presence, and blessing them with the vision of himself here and hereafter; see Matthew 5:8; this may likewise be understood of Christ, who, in his human nature, is pure from all sin, both original and actual: he indeed took upon him the sins of his people, and bore them, and made satisfaction for them, and brought in everlasting righteousness; which being done, God has showed himself pure to him, by justifying, acquitting, and discharging him from all such sins; by accepting his righteousness, and imputing it to those for whom he wrought it;
and with the froward thou wilt show thyself froward; or "thou wrestlest" b, or wilt contend with them until they are destroyed: the same word is here used which Naphtali has his name from, Genesis 30:8. The froward are such as are of perverse dispositions, and of stubborn and obstinate tempers, and whose ways are crooked and distorted; and such were the people of the Jews in the times of Moses, and of Christ,
Deuteronomy 32:5; and who seem here to be designed; even the Jews in Christ's time, who were just the reverse of the above characters, were cruel and unmerciful, faithless and hypocritical, filthy and pure, disbelieved the Messiah, rejected and crucified him, were contrary to God, and to all men; and therefore God walked contrary to them, as he threatened, Leviticus 26:27; the same as showing himself froward to them; for God is not froward and perverse in himself, nor in his ways, which are all equal, just, and pure: and though there is one and the same word used in our version, yet there are two different words in the Hebrew text; the same word that is used of the froward is not used of God; that which is used of God, as before observed, signifies wrestling, and designs God's contending with the people of the Jews, in a way of wrath and fury, which came upon them to the uttermost, and issued in their entire ruin as a people and nation; the words here had their fulfilment in the destruction of Jerusalem.
b תתפתל "eluctaris", Junius Tremellius "colluctaris", Aben Ezra; "reluctaris", Gejerus; "certas", Schmidt.