Wei Wuxian does not need to put his hand on Lan Zhan's to tell him to remain peaceful; he knows Lan Zhan both knows and respects his wishes. But he needs Jiang Cheng to see him do it and so he reaches out, holding Lan Zhan's hand still. "It's fine," he says, then turns his attention back to Jiang Cheng. "You know that I care about our family! If I didn't care, I wouldn't be telling you to go home!"