With the help of the chirpy Fox & Friends host, Trump just admitted, on camera, that he made up the premise for the tweet warning former FBI Dir. James Comey that he better “hope” (he hopes a lot doesn't he?) there were no  “Tapes” of their conversations. His reason being, to “keep him honest “ on the stand and not change his story- i.e. influence his testimony. 

www.politicususa.com/...

Legal experts say Donald Trump added to his legal jeopardy and the potential obstruction of justice case against him during an interview on Fox News. The part of the interview that added to Trump's woes was set up by a Fox and Friends host flattering the President by saying he was smart to lie about the Comey tapes.

He is on record as having threatened adversaries with the possible existence of tapes prior to court testimony, so he went to his old bag of tricks. 

Yesterday a CNN columnist made the case that this one tweet from Trump will likely be the single most consequential and damaging tweet of his presidency, and that was before this, um, faux pas. 

IANAL, but me thinks  there   may  just be a law against such behavior? No doubt SC Mueller is on this already. Thanks Fox & Friends dummy!

TRUMP: But, when he found out that there may be tapes out there, whether it’s governmental tapes or anything else, and who knows, I think his story may have changed. I mean, you’ll have to take a look at that because then he has to tell what actually took place at the events. And my story didn’t change. My story was always a straight story. My story was always the truth. But you’ll have to determine for yourself whether or not his story changed. But, I did not tape.

EARHARDT: That was a smart way to make sure he stayed honest in those hearings.

TRUMP: Well, it wasn’t very stupid, I can tell you that

Actually, it was really stupid Donnie. Even by your standards.  I can tell you that.