The sermon was full of hackneyed phrases and platitudes.
If you describe something such as a saying or an image as hackneyed, you think it is no longer likely to interest, amuse or affect people because it has been used, seen, or heard many times before. Power corrupts and absolute power absolutely corrupts. That's the old hackneyed phrase, but it's true. a hackneyed phrase is boring and does not have much meaning because it has been used so often (hackney (16-19 centuries), from hackney (14-20 centuries), probably from Hackney, area in London, England where horses were once kept)
repeated too often; overfamiliar through overuse; "bromidic sermons"; "his remarks were trite and commonplace"; "hackneyed phrases"; "a stock answer"; "repeating threadbare jokes"; "parroting some timeworn axiom"; "the trite metaphor `hard as nails'"
To devote to common or frequent use, as a horse or carriage; to wear out in common service; to make trite or commonplace; as, a hackneyed metaphor or quotation