In the Ming story An Old Student Repays a Favor Over Three Generations (老门生三世报恩), the examiner Kuai prefers young candidates. Three times, without meaning to, he passes the same old man, Xianyu Tong. Xianyu passes the provincial examination at fifty-seven and the metropolitan examination at sixty-one.
Xianyu later clears Kuai’s son of a false charge. “This only repays a little of my teacher’s kindness,” he says. “I still owe much feeling.” He then keeps Kuai’s grandson at his official residence to study and gives him three hundred taels. Kuai thinks: “Plant thorns and get thorns. Plant peach and plum trees and get shade.”