name of ... Lord - that is, Jehovah Himself (Psa 44:5; Psa 54:1); represented as a storm approaching and ready to burst over the Assyrians (Isa 30:30, Isa 30:31).
burden ... is heavy - literally, “grievousness is the flame,” that is, the flame which darts from Him is grievous. Or else (as the Hebrew means an “uplifting”) the uprising cloud is grievous [G. V. Smith]; the gathering cloud gradually rising till it bursts.