“The drive-by media is attempting to persuade and convince people that Donald Trump told people to drink Drano at the White House press briefing,” the radio host Rush Limbaugh said dismissively on his Friday show. “That Donald Trump told people to go out and get a syringe and inject Clorox in their arms, and that this could be dangerous.”

Here is what Mr. Trump said at Thursday’s briefing: “I see the disinfectant that knocks it out in a minute, one minute. And is there a way we can do something like that by injection inside, or almost a cleaning? Because you see it gets inside the lungs, and it does a tremendous number on the lungs, so it would be interesting to check that.”

Joel B. Pollak, the senior editor at large at Breitbart News, wrote about that statement in a column that ran under the headline “Fact Check: No, Trump Didn’t Propose Injecting People With Disinfectant.”

“Trump used the word ‘inject,’ but what he meant was using a process — which he left ‘medical doctors’ to define — in which patients’ lungs might be cleared of the virus,” Mr. Pollak wrote. (Breitbart later retracted its “fact check” headline, saying the column “should have been framed as an opinion piece.”)

The White House press secretary, Kayleigh McEnany, issued a statement on Friday accusing the news media of taking Mr. Trump’s words “out of context.” That was before Mr. Trump claimed that he had spoken “sarcastically,” to get a rise out of journalists.

Neil Cavuto, a Fox host who has been critical of Mr. Trump, was not impressed with that excuse. “I think it’s important on the president to say and come out unequivocally: ‘Some of you took me seriously, even though I sounded serious saying it. Please do not. Please do not even consider injecting some of this stuff into your system,’” Mr. Cavuto said during a Friday appearance on Fox Business.

It was not the first time that Mr. Trump has offered medical advice on how to combat the virus. For weeks, he touted the use of a malaria drug, hydroxychloroquine, from behind a lectern with the presidential seal.