Psalm 3 is supposed to have been written by David during his flight from the revolt of his son Absalom. (Harem conspiracies are not just an Egyptian thing.) What is interesting about the Septuagint version (which is the ancient Greek translation) of the Psalm is that salvation is equated with the destruction of his enemies (in this case his son). In Greek, salvation is a many faceted concept and the destruction of enemies is certainly one of the facets.