This verse, recited as part of U’va l’Tziyon, contains the word “Selah.” This meaning of this word – which only occurs in the book of Psalms – is the subject of some discussion. The Talmud (Eiruvin 54a) includes it in a list of words that mean “forever” or “never-ending.” Other words that carry this meaning include “netzach” and “va’ed.”