on Psalms 18 :26
With the froward - עקש ikkesh, the perverse man; he that is crooked in his tempers and ways.
Thou wilt show thyself froward - תתפתל tithpattal, thou wilt set thyself to twist, twine, and wrestle. If he contend, thou wilt contend with him. Thou wilt follow him through all his windings; thou wilt trace him through all his crooked ways; untwist him in all his cunning wiles; and defeat all his schemes of stubbornness, fraud, overreaching, and deceit.
My old Psalter has, With the wiked thow sal be wike. Here the term wicked is taken in its true original sense, crooked, or perverse. With the wiked, the perverse, thou wilt show thyself wike, i.e., perverse; from to draw back, to slide. As he draws back from thee, thou wilt draw back from him. It may, as before intimated, come from to seek for enchantments; leaving God, and going to devils; to act like a witch: but here it must mean as above. The plain import is, "If thou perversely oppose thy Maker, he will oppose thee: no work or project shall prosper that is not begun in his name, and conducted in his fear."
on Psalms 18 :26
With the pure - Those who are pure in their thoughts, their motives, their conduct.
Thou wilt show thyself pure - They will find that they have to deal with a God who is himself pure; who loves purity, and who will accompany it with appropriate rewards wherever it is found.
And with the froward - The word used here - עקשׁ ‛iqqêsh - means properly perverse; a man of a perverse and wicked mind. It is derived from a verb - עקשׁ ‛âqash - which means, to turn the wrong way, to wrest, to pervert. It would be applicable to a man who perverts or wrests the words of others from their true meaning; who prevaricates or is deceitful in his own conduct; who is not straightforward in his dealings; who takes advantage of circumstances to impose on others, and to promote his own ends; who is sour, harsh, crabbed, unaccommodating, unyielding, unkind. It is rendered perverse in Deuteronomy 32:5; Proverbs 8:8; Proverbs 19:1; Proverbs 28:6; froward here, and in 2 Samuel 22:27; Psalm 101:4; Proverbs 11:20; Proverbs 17:20; Proverbs 22:5; and crooked in Proverbs 2:15. The word does not occur elsewhere in the Old Testament.
Thou wilt show thyself froward - Margin, wrestle. In the corresponding place in 2 Samuel 22:27 it is rendered, "Thou wilt show thyself unsavory;" though the same word is used in the original. In the margin in that place, as here, the word is wrestle. The original word in each place - פתל pâthal - means to twist, to twine, to spin; and then, to be twisted; to be crooked, crafty, deceitful. In the form of the word which occurs here (Hithpael), it means, to show oneself crooked, crafty, perverse. (Gesenius, Lexicon). It cannot mean here that God would assume such a character, or that he would be crooked, crafty, perverse in his dealings with men, for no one can suppose that the psalmist meant to ascribe such a character to God; but the meaning plainly is, that God would deal with the man referred to according to his real character: instead of finding that God would deal with them as if they were pure, and righteous, and merciful, such men would find that he deals with them as they are - as perverse, crooked, wicked.
on Psalms 18 :26
18:26 Pure - Free from the least mixture or appearance of unrighteousness, or unfaithfulness. Froward - Thou wilt cross him and walk contrary to him.