In verse 8 brethren and companions are the psalmist’s fellow Israelites who live in Jerusalem; and it is for their sake and for the sake of the Temple (verse 9a) that the psalmist wishes peace for the city and prays for her prosperity (your good). For the sake of may be rendered here “Because I love…” or “Because I am concerned for….” As in verse 7, the command Peace be within you will have to be shifted in some languages to say, for example, “People of Jerusalem, live in peace” or “… live peaceably together.”

In verse 9b I will seek may be taken to indicate activity; it seems more likely, however, that here, as elsewhere, the word is a synonym for prayer (so Cohen, Anderson); see Bible de Jérusalem “I pray,” Bible en français courant “I ask for.” “Your prosperity” (Good News Translation) refers to the city of Jerusalem. As Toombs says, “He values the city, not because it is the nation’s capital, but because it is the place where God’s temple, his earthly home, is established.” For the sake of the house of the LORD our God may be recast in some languages to say “Because I love the Temple of the LORD, who is the God we worship” or “I love the LORD our God’s Temple; therefore I pray that God will make Jerusalem prosper.”

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 .