The Tang dynasty from 618 to 907 AD was one of the great eras of Chinese history. In the capital lived one Pan Guo, whose skill as a martial artist earned him a post in the government offices when he was still very young. He was easy to get along with, so he made many friends among the other young men working there.

One day, a group of them was walking along by a cemetery. Among the tombs, Pan spotted a goat that a shepherd had forgotten. The goat was minding its own business, eating the grass. Pan and his friends surrounded it and dragged it off towards home. The goat started bleating. They were afraid the shepherd would hear and come after his goat, so Pan reached in and pulled out the goat's tongue by the roots. He was proud of his quick wits.
　　
After they got home, they slaughtered the goat and roasted it. They washed it down with a lot of wine and had a good time.　　

In the following year, Pan was horrified to discover his tongue shrinking. As it got shorter and shorter, Pan lost his speech. He couldn't carry out his official duties, so he quit his job. He had to find some way to cure his tongue.
　
His boss, Zheng Yuqing, suspected Pan was just being lazy, so he ordered him to open his mouth to prove whether or not he was really sick. He was surprised to see that Pan's tongue had already disappeared. All that was left was a little stub at the root. He demanded to know what had happened. Pan took up a brush and wrote, "It must be because a bunch of us were stealing a goat last year,and when the goat started bleating, I ripped its tongue out."
　
Zheng Yuqing knew that Pan lost his tongue to balance the tongue he took from the goat. He ordered his subordinates to carry out Buddhist services to bring the goat fortune to compensate for its loss. He told Pan to copy the Lotus Sutra.　

Pan was sorry for what he had done. He swore never again to eat the flesh of an animal, and to do his best to bring the goat fortune through good deeds, dharma services, and prayers.　

After a year, his tongue began to grow back.　　

When he found his tongue was growing back, Pan was thrilled. He ran to the office to report to Zheng. Zheng was proud of Pan for his determination to correct his mistake. When he could speak normally again, he promoted him. Zheng Yuqing was so honest and wise that people always praised him. The word of his good deeds reached the Emperor TaiZong, one of the best emperors in Chinese history, and in the 9th year of his reign, 635 AD, Zheng Yuqing was promoted to the post of Imperial Censor, one of the highest positions in the Empire.

Zheng told the Emperor that perhaps he won his promotion to balance the fortune he had won for the goat that lost its tongue.(From The Story About Free Captive Animals)