In an interview with CNN's Jake Tapper on "State of the Union" Sunday, Trump stood by his assertion that media scrutiny of Carson's accounts of his past is the beginning of his campaign's end.
"It certainly is. It's a lot of scrutiny and frankly, it's a lot of statements that are under fire, and I hope Ben's going to be OK with it. It's going to be interesting to see what happens -- time will tell," Trump said.
He said he hopes Carson "comes out great" from the scrutiny.
But Trump also implied that Carson's story about attempting to stab someone in his youth -- only to have his knife broken when he hit a large belt buckle -- was hard to believe.
"Belt buckles really pretty much don't stop stabbing," Trump said. "They turn, they twist, things slide off them -- pretty lucky if that happened."
Trump said Carson's description of his childhood temper as "pathological" is disturbing.
"It's a serious statement when you say you have a pathological disease, because if I understand it, you can't really cure it," Trump said.
Speaking on CBS' "Face the Nation" Sunday morning, Trump also cited Carson's belief that the pyramids were built to store grain
as another reason to question his judgment.
"So, you're talking about storing grain in the pyramids. Well, they have very little space. They have space for small rooms, where the pharaohs had their coffins and where the pharaohs were buried, essentially," Trump told host John Dickerson. "So, a lot of -- a lot of things are going on. And I don't know. I just don't know what to think. I hope it -- I hope it works out fine for Ben. I just don't know what to think."
Trump also took a shot at Carson over "Saturday Night Live," which Trump hosted this weekend. Carson has said he wouldn't appear on the show, as the presidency is a "very serious thing."
Trump told Tapper he asked to take out a couple of skits he considered too risqué but added that presidential candidates don't say no to "Saturday Night Live" or the CBS news show "60 Minutes."
"He would have done it if they asked him," Trump said of Carson. "You have to get asked. You know, it's not easy to be asked."