Get it? He said we'll see who gets overthrown, while literally throwing someone! Ha ha, good one Namor!
That scene was drawn by Herb Trimpe and Jim Mooney and written by Bill Mantlo, originally for 1976's Super-Villan Team-Up #4. It's one of the fifty or so instances of Namor hurling someone or something within the pages of Essential Super-Villan Team-Up Vol. 1, a 550-page collection consisting almost entirely of scenes of Namor and Dr. Doom yelling at each other.