Presidential candidate Pete Buttigieg (D) heckled President Donald Trump on Thursday with a Chinese proverb about walls a day after Trump mocked him at a campaign rally.

“I was thinking of a Chinese proverb that goes ‘When the wind changes, some people build walls, some people build windmills,'” Buttigieg said in response to Trump’s remarks about him. “You got to recognize we need something completely different than what we have in this White House.”

During a Wednesday evening Florida rally, Trump name-checked “Boot-edge-edge” and mocked the South Bend, Indiana, mayor, sarcastically saying that Buttigieg would be “great” representing America against the Chinese in trade negotiations.

“He’s got a great chance, doesn’t he? He’ll be great,” Trump said at the rally. “He’ll be great representing us against President Xi of China. That’ll be great. I want to be in that room, I wanna watch that one.”

In an interview with Today co-host Craig Melvin this week, Buttigieg vowed not to play Trump’s game if he wins the nomination, conceding that nobody is better at in-your-face politics than the president.

“I have a very different energy than this president. There’s going to be a temptation to try to play his game,” Buttigieg said, adding that he would not care if Trump called him a “low-energy” candidate. “If you’re playing his game, you’re losing.”