John Trapp on Isaiah 26:3

Ver. 3. Thou wilt keep him in perfect peace] Heb. peace, peace, that is, a multiplied peace with God, with himſelf, and with others; or a renewed, continued peace, or a perfect, ſheer pure peace, as One ſenſeth it. What the old Tranſlatour here meaneth by his Vetus error abiit, is hard to ſay. An excellent deſcription of true ſaving Faith may be taken from this Text: and Mr. Bolton maketh mention of a poor diſtreſſed ſoul relieved by faſtening ſtedfaſtly in his laſt ſickneſs on theſe ſweet words: ſaying that God had graciouſly made them fully good to him.

Becauſe he truſteth in thee] So far as a ſoul can ſtay on and truſt in God, ſo far it enjoyeth a ſweet peace, and calm of ſpirit: perfect truſt is bleſſed with perfect peace. We have a famous inſtance for this in our bleſſed Saviour, Joh. 12.27, 28. Wherefore gird up the loins of your mind, be ſober, and hope perfectly for the grace that is to be brought unto you at the revelation of Jeſus Chriſt, 1 Pet. 1.13.