Selah is a somewhat enigmatic word! The Talmud, Tracate Eruvin 54a, states that it means forever. The Radak, Rabbi David Kimche, one of the classic commentaries on the Bible explained that it is a musical notation for the singers to raise their voices. The Ibn Ezra, another classic early commentary, understands it to mean “true and certain”. Rabbi Samson Raphael Hirsch, one of the greatest experts on the etymology of Biblical words, explains that typically selah remains untranslated because it has no intrinsic meaning. Rather, it is poetic and adds extra emphasis.