He was a guest on Don Imus' radio show back in the mid-2000s and he was ranting and hyperventilating about the Bush administration over some issue or another. He actually dropped a couple of four-letter words that got bleeped off the air on the radio, and Imus scolded him (I'll paraphrase it as best I can):
IMUS: "Why are you swearing at me on the air like that?"
MATTHEWS: "I'm sorry, Don. Sometimes I get carried away. Don't get upset ... I do this on my show sometimes, too."
IMUS: "Yeah, but I actually have an audience here!"
ROFL.
IMUS: “Our next guests on the show are a bunch or nappy-headed hos.”