This strophe essentially repeats the thought of verse 1; the advice is to wait patiently for Yahweh to act; the success and prosperity of the evil will soon be ended. Yahweh is the one to decide how and when wicked people will be punished, people who now “prosper” and “succeed in their evil plans” (Good News Translation). Be still before the LORD means to be quiet in the LORD’s presence and not be constantly and impatiently complaining about the success of the wicked. The command Be still before the LORD in the Good News Translation sense of “Be patient” is often expressed idiomatically; for example, “Don’t cause noise in the heart,” “Walk softly,” or “Sit coolly.”

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 .