《太平广记·卷二百四十八·诙谐四》
结婚几个月后，媳妇家怀疑姑爷不聪明，于是岳父家特意置办了一桌酒席，将亲友都请来，准备在酒桌上，好好试探考问一下姑爷。开宴后，岳父问姑爷：我姑爷在山东读书，按说是有知识懂得道理，你能说说鸿雁与仙鹤为什么会鸣叫吗？
妇家置酒，盛会亲戚，欲以试之。问曰：某郎在山东读书，应识道理，鸿鹤能鸣何意？
A few months after the marriage, the wife's family suspected that the son-in-law was not smart, so the father-in-law's family specially prepared a banquet, inviting relatives and friends, and planned to test the son-in-law properly at the dinner table. After the banquet started, the father-in-law asked the son-in-law: My son-in-law studied in Shandong, so you should have knowledge and understand the principles. Can you tell me why wild geese and cranes sing?