Introduction to Zhangren Peak: In the northwest of Yuhuangding is Zhangren Peak, which is famous for its shape like an old man’s stoop. In ancient times, the old man was respectfully called father-in-law. In addition, there were several handsome small stones nearby, so it was also known as "the old man and his grandson". Since ancient times, people have called their wife's parents "father-in-law and mother-in-law," "father-in-law and mother-in-law," or "Taishan Taishui." This is mainly based on the "Big mountains and rivers have Mount Yue, and small mountains and rivers have Mount Yue-in-law." Come. "Youyang Zazu" says: Xuanzong granted Zen to Mount Tai, and Zhang Shuo was granted the title of Zen envoy. His son-in-law Zheng Yi was originally a ninth-rank official, but was promoted to fifth-rank official after being granted Zen status. Xuanzong was very surprised to see Zheng Yi's rise in officialdom, so he asked Zheng Yi, but Zheng Yi had no words to answer. Huang Banchuo on the side said: This is the power of Mount Tai. With a double entendre, Xuanzong acquiesced. Therefore, since the Tang Dynasty, "Taishan" and "father-in-law" have become the specific terms for the wife's father, and "father-in-law" has also evolved from referring to the elderly in general to the wife's father.