21. Therefore—In order that all may be turned from idols to Jehovah, He will now give awful proof of His divine power in the judgments He will inflict.
this once—If the punishments I have heretofore inflicted have not been severe enough to teach them.
my name … Lord—Jehovah (Ps 83:18): God's incommunicable name, to apply which to idols would be blasphemy. Keeping His threats and promises (Ex 6:3).