Trump's story continued: "And he plunged it into the belt and amazingly the belt stayed totally flat and the knife broke."
Trump then plunged a rhetorical knife of his own to the Iowa crowd: "How stupid are the people of Iowa? How stupid are the people of the country to believe this crap?"
Not atypical of Mr. Trump, he didn't just have barbs for Dr. Carson. Trump also punched at the GOP's favorite target, Hillary Clinton.
But went further than his fellow Republicans saying: "She's playing the woman card. Outside of the woman card, she's got nothing going."
The GOP frontrunner also had words for President Obama, specifically his administration's accomplishment of killing Osama bin Laden.
"Pretend anybody is president," Trump said as he set the stage for the theoretical circumstance. "These great guys come in, general, 'Mr. President, we have Osama bin Laden. So we have a choice, we can leave him alone Mr. President, or we can take him and bomb the hell out of him.'
"Who's gonna say leave him alone?" Trump exclaimed, intimating that the decision to go in was a no-brainer. "Is there anybody that would say it?"
Asked Thursday night to respond to Trump's comparison to child molesters, a Carson spokesman wrote, "The campaign has no comment."