Washington CNN  — 

Ben Carson’s top adviser says it is “sad” watching Donald Trump bash his Republican presidential opponent, and that Carson’s reaction is to “pray for him.”

The neurosurgeon’s business manager Armstrong Williams said Friday that Trump’s Thursday night rant on Carson – and interview comparing him to child molesters – doesn’t get a rise out of Carson.

“It is so immature; it is so embarrassing,” Williams said Friday on CNN of Trump. “I feel so sorry for him.”

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Speaking with CNN’s Chris Cuomo on “New Day,” Williams said he talked with Carson after Trump went on a 95-minute tirade in Iowa that included mocking Carson’s stories of a violent past. This followed an interview with CNN’s Erin Burnett, in which, Trump compared Carson’s history of a temper to a child molester, citing that since referred to himself as “pathological,” that meant he couldn’t cure his anger.

Carson’s response?

“‘Pray for him,’” Williams said.

“Dr. Carson (was) 14 years old at the time, it was a half century ago. Mr. Trump speaks of this as if it happened within the last year,” Williams said of the criticism. “I mean, are you kidding me? It’s so sad watching and listening to him.”

Trump on Thursday said Carson’s tales from his youth, including trying to hit his mother with a hammer and stabbing a friend, only to have the blade stopped by a belt buckle, are hard to believe.

“How stupid are the people of Iowa? How stupid are the people of the country to believe this crap?” Trump asked an appreciative audience.

Williams said Trump “cannot fathom” how anyone could be doing better than him in the Republican race.

“Obviously, he only wants to be on the stage by himself, crowned the nominee and run against the eventual Democratic challenger,” Williams said.

“To see him imploding before our very eyes is … just sad to watch.”