Trump's a known Faux News addict, of course, and listens to li'l Tucker all the time. Evidently Carlson came out strongly against an attack on Iran at this time, and Trump may well have taken that to heart.

https://www.buzzfeednews.com/article/hayesbrown/why-did-trump-pull-back-from-bombing-iran-it-depends-on-who

"And, as the Washington Post's Josh Rogin tweeted, there's not a small amount of speculation in Washington that Trump could have made the decision to call off the strikes while watching Fox News host Tucker Carlson's show on Thursday night. Carlson, the Daily Beast reported on Wednesday, has reached out to the president directly to advise him against attacking Iran and spent last night's show railing against the calls for war coming from Washington."

I'm not sure whether to salute them both or be appalled by that, if that's the reason...:)