It’s in the article linked in the #1 reply.
Here’s the short version:
“Reid J. Epstein ;@reidepstein · 3h3 hours ago
EPN spox to @davidluhnow: EPN told Trump no wall $$, Trump didnt react. “Mr. Trump was not lying ... because there was no discussion.” “
(’EPN spox’ is Mexican President’s spokesman)
I agree. If Mr. Trump didn't respond to the Mexican President saying "We will not pay for the wall" then there was no discussion. It was just a comment.