President Donald Trump briefly left the hospital Sunday in his car to wave to supporters gathered outside.

The president’s visit came shortly after he promised his supporters “a surprise” in a video posted a video on social media.

“It’s been a very interesting journey,” Trump said in the video. “I learned a lot about COVID. I learned it by really going to school. This is the real school. This isn’t the let’s read the books school. And I get it, and I understand it. And it’s a very interesting thing.” Earlier in the day, Trump’s doctor said he “continued to improve” and suggested he could be discharged as early as Monday.