The opening sentence is a question that includes a question, both of which are rhetorical. It may be better to use a negative statement for the larger question, as follows: “The people of other nations should not say…” or “God, don’t let the people of other nations ask us….” The enemies of the Israelites should not be able to put them to shame by asking Where is their God? (see 42.3, 10; 115.2). Good News Translation has the question addressed to the Israelites. Bible en français courant translates “What is their God doing?” Such a question was humiliating in the extreme, because there was no answer they could give; God had remained silent, impassive, inactive, while his people suffered.

So they pray for vengeance (verse 10c-d). The language of these two lines can be hard to understand if a literal translation is attempted (see Revised Standard Version). For comments on “vengeance” in the sense of “punish,” see 18.47. The outpoured blood of thy servants means “the killing of your servants (or, your people).” Let the avenging … be known among the nations means “let the nations experience (or, feel).” Most translations take “know” to mean “learn, realize” (so Bible en français courant, Traduction œcuménique de la Bible); Biblia Dios Habla Hoy translates “Allow us to see the death of your servants avenged! And may the pagans also know it!” But it seems better to see here the meaning “to experience,” that is, that they, the pagans, suffer God’s punishment; so New English Bible “Let thy vengeance … fall on those nations,” and New Jerusalem Bible “Let us see the nations suffer vengeance for shedding your servants’ blood.” Before our eyes means “while we look on.” In some languages it may be necessary to render the second half of verse 10 as “Let us watch you as you kill the other tribes for having killed your people,” or “We pray that we may be able to see…,” or “We ask you to allow us to see….”

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 .