He 'waxed eloquent' [=he said many things] on/about the pleasures of gardening.
His success serves as an 'eloquent' reminder of the value of hard work.
She spoke 'eloquently' about the need for better schools.
(..) what's been cleaned? Tuesday, I did your lino. No, this room, this is where we'll find it. Any break in the dust line. You can put back anything but dust. Dust is eloquent. What's he on about? Cameras, we're being watched. What?! Cameras? Here? I'm in my nightie! No, Inspector. Why? (..)2012 TvShow: Sherlock Title: The Reichenbach Fall Season: 2 Episode 3