Yuan looks a little horrified at the suggestion that the chief cultivator taste the tea - he doesn't want to blurt out his suspicions in case he's wrong, but he also doesn't want to risk the possibility that Lan Wangji may drink poison that was meant for Jin Ling - and, he realises with a dizzying wave of fear, for him, too. He doubts he would have been anything more than collateral damage, but the idea that he might have drunk it if Jin Ling hadn't stopped him makes him feel a little unsteady on his feet.

Jin Ling steps in instead, which makes him even more certain that the problem is far, far more serious than the tea simply being stale - why else would he be so determined that nobody drink it. He's about to throw caution to the winds and say something when Lan Wangji speaks up and he has to stop himself breathing a sigh of relief. It wouldn't have meant much coming from him, but from the chief cultivator? People will have to pay attention - and they do, a gasp ripples around the room at those words.

"That does seem to be the obvious conclusion, doesn't it?" Wei Wuxian says smugly "Jin-zongzhu, if we promise nobody will drink it, would you allow his excellency to inspect the tea?"

Look he's being properly polite and everything.