We are all sinners; and Christ came into the world to save sinners, to teach sinners, to call sinners to repentance. We value a promise by the character of him that makes it; we therefore depend upon God's promises.
All the paths of the Lord, that is, all his promises and all his providences, are mercy and truth. In all God's dealings his people may see his mercy displayed, and his word fulfilled, whatever afflictions they are now exercised with.
All the paths of the Lord are mercy and truth; and so it will appear when they come to their journey's end. Those that are humble, that distrust themselves, and desire to be taught and to follow Divine guidance, these he will guide in judgment, that is, by the rule of the written word, to find rest for their souls in the Saviour.
Even when the body is sick, and in pain, the soul may be at ease in God.