In verses 7-9 the psalmist remembers the giving of the Law at Sinai (his precepts, verse 7b) and the covenant Yahweh made with his people there.
In verse 7a Good News Translation “all he does” translates the Masoretic text The works of his hands (some Hebrew manuscripts and early versions have “the work…”). Faithful and just translates ʾemet (see comments on 15.2) and mishpat (see 7.6); trustworthy (verse 7b) translates a form of the verb ʾaman “be sure, firm, dependable” (see 36.5). The word for precepts is used also in 19.8a; 103.18b (“commandments”). For translation suggestions regarding “faithful,” see discussion on “loyal” in 18.25. His precepts are trustworthy must be recast in some languages to say, for example, “when he orders people to do something, they can trust what he says.”
In verse 8a established translates the passive participle of the verb “to support”; here it means “firm, immovable, unshakable.” If the translator has used a clause in verse 7 to express “his commands,” it may be necessary to switch to “words” in verse 8; for example, “his words last forever.”
In verse 8b the Hebrew verb is the passive participle of the verb “to do.” Revised Standard Version takes the people as the implied agent of the passive to be performed; Good News Translation has Yahweh as the agent of the action “they were given” (also New English Bible, New International Version, New American Bible, Bible de Jérusalem, New Jerusalem Bible, Bible en français courant, New Jerusalem Bible, Traduction œcuménique de la Bible, Biblia Dios Habla Hoy, Dahood; see New American Bible “wrought in truth and equity”). Faithfulness (Good News Translation “truth”) here translates ʾemet (as in verse 7a), and uprightness (Good News Translation “righteousness”) translates a term for “straight, upright” (see “upright in heart” in 7.10; 11.2). The statement “they were given in truth and righteousness” can be stated “Yahweh acted in a true and righteous manner when he gave his commands,” or in some languages, “God did what was true and right when he told his people what to do.”
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 .