This verse is placed outside the quotation marks of verses 1-3 by Revised Standard Version; Good News Translation includes it as part of what the congregation recited in verses 2-4.
In line a the Hebrew text may be read The LORD is righteous (Revised Standard Version, New International Version) or “the LORD, the righteous one” (Good News Translation, New Jerusalem Bible, New Jerusalem Bible). The LORD is righteous or Good News Translation‘s rendering may be translated as “The LORD, who is faithful” or “The LORD, who is loyal to his people.”
The language of line b is not quite clear; Good News Translation takes the cords of the wicked as a figure of slavery (see the use of “cords” in 2.3). Cohen suggests that the figure is that of an ox, tied by cords to a plow (see Job 39.10). Biblia Dios Habla Hoy translates “has freed me from the domination of the wicked.” In languages in which the figure of being freed from slavery is not clear, it will be better to follow such a model as Biblia Dios Habla Hoy or say, for example, “he has freed me from wicked people.” Or else Die Bibel im heutigen Deutsch can be followed: “He has cut the cords of my enemies, with which they force me to work as a slave.”
Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .