The source of "Good medicine is better for the sick than the bitter taste" is from "Confucius' Sayings - Six Books".

1. "Good medicine tastes bitter and is good for the sick, and loyal words are good for the ears and the ears" is not a poem, but from "Confucius' Family Words - Six Books".

2. "Confucius' Family Tales - Six Books": 100,000 righteous soldiers of Liu Bang, the Duke of Pei, broke through the _Guan, defeated the Qin Dynasty's Guanzhong defenders in Lantian, and led the world's righteous army to enter Xianyang without any difficulty. After entering the Xianyang Palace of the Qin Dynasty, Liu Bang, the Duke of Pei, was attracted by the beauty and treasures in the palace and was so forgetful that he was ready to stay in the palace to have a good time and not to come out. His brother-in-arms, Fan Kuai, tried to persuade him to stay in the palace, but he would not listen to him. At this time, Zhang Liang came into the palace to admonish him, and severely criticized Liu Bang, explaining the mistake of doing so, and said this: "Loyal words are good for the ears, and poison is good for the mouth, please listen to Fan Kuai's words." Only then did the Duke of Pei reluctantly leave the Qin Palace, announcing that the army would drive out of the city and be stationed obediently at Bashang, on the outskirts of Xianyang, and would not be allowed to disturb the people.

3. "Good medicine tastes bitter and is good for the sick, but loyal words are good for the ears," is a Chinese idiom that describes how one should humbly accept other people's opinions and criticisms, or how one should educate people to be brave enough to accept criticisms. Most of the good medicine has a bitter taste but is good for curing diseases, while most of the words that teach people to be good are not very pleasant to the ear but are good for people to correct their shortcomings. This sage is teaching people to be brave enough to accept criticism, and is often used to illustrate that one should treat others' opinions and criticisms correctly.