John Trapp on Psalms 26:4

Verſ. 4. I have not ſate with vain perſons] who are voyd of Gods holy fear, but filled with all unrighteouſneſs, wickedneſs, covetouſneſs, maliciouſneſs, &c. Rom. 3.29. Courtiers are ſuch for moſt part, and David never delighted in ſuch company, to ſit with them, eſpecially when they were acting miſchief; which whiles Gromwell did at the condemnation of Lambert Martyr, and Sir John Cheek, at other ſuch like meetings, they were caſt upon no ſmall ſnares and inconveniences. See Jer. 15.17.

Neither will I go in with diſſemblers] Heb. cloſe workers of iniquity,Qui ſecreto malè agunt, Chald. ſecret and ſly Sirs, ſuch as hide themſelves to do evil, as the Chaldee hath it, and can carry their wickedneſs cleanly and cloſely, ſo as that the World ſhall be little the wiſer, Verſatiles & verſutili, multiplices, Protei; ſuch as can ſerve the times, and ſhift their ſails to the ſitting of every Wind, Machiavellians, Ahitophels, Jonadabs, 2 Sam. 13.3. Theſe mens wiſdom may ſerve them, as the Oſtriches wings, to make them out-run others upon earth, though it be into Hell-mouth, but help them never a whit toward Heaven; David therefore would have nothing to do with them, he would neither enter, walk, nor ſit with any ſuch (Confer Pſal. 1.1.) they ſhould not ſprinkle him with their Court-holy-water.