This passage comes from the first chapter of The Analects, "Xue Er": "Youzi (a disciple of Confucius) said: 'When trustworthiness (Xin) is close to righteousness (Yi), one's words can be fulfilled. When respect is close to propriety (Li), one stays far from shame and disgrace. If one does not lose the support of those close to them, they are worthy of being followed.'" Ancient Chinese Confucianism advocated following the "Five Constant Virtues" (Wuchang) in personal conduct: Ren (Benevolence), Yi (Righteousness), Li (Propriety), Zhi (Wisdom), and Xin (Trustworthiness). As one of these five virtues, Xin (Trustworthiness) plays an important normative role in people's daily lives.
A person must be trustworthy; without trust, one cannot stand firm. Promises made must be kept. Zi Lu (a courageous and direct disciple of Confucius) in The Analects was such a person. There is a famous historical story about "Ji Bu's promise worth a thousand gold pieces." During the end of the Qin Dynasty, there was a man named Ji Bu who valued trustworthiness and Yi (Righteousness) greatly. As long as he agreed to something, he would find a way to fulfill it. A saying circulated at the time: "It is better to gain Ji Bu's promise than a thousand catties of gold." During the Chu-Han contention, Ji Bu, a fierce general under Xiang Yu, repeatedly troubled Liu Bang, who harbored a deep hatred for him. After Liu Bang won the empire, he offered a reward for Ji Bu's capture, forcing Ji Bu to flee. The renowned knight-errant Zhu Jia, knowing Ji Bu's character well, not only sheltered him but also used his old acquaintance Xiahou Ying (a trusted minister of Liu Bang) to plead for Ji Bu's pardon. Fortunately, Liu Bang was magnanimous and admired Ji Bu's abilities; he forgave past grievances and appointed him as a Gentleman of the Palace. Zhu Jia was willing to risk the extermination of his entire clan to provide Ji Bu with a hiding place, rather than betray him for the reward of a thousand gold pieces. This shows that Zhu Jia was deeply moved by Ji Bu's quality of honoring his promise as if it were worth a thousand gold pieces, and willingly put himself in danger for Ji Bu's sake.
However, keeping one's word must align with Yi (Righteousness); only promises that conform to righteousness can be fulfilled. When Confucius left the State of Chen for the State of Wei, he passed through Puyi, where Gongshu Shi (a nobleman of Wei) had occupied the area and rebelled against Wei, and the people of Pu detained Confucius. Confucius's disciples then fought fiercely with them. Frightened, the people of Pu said to Confucius, "If you promise not to go to Wei, we will release you." After reaching an agreement, they let Confucius and his party leave through the east gate. Once safe, Confucius proceeded directly to Wei. Zi Gong (a disciple) asked, "Can an agreed-upon covenant be broken?" Confucius replied, "A covenant made under coercion is not recognized by the spirits." Confucius believed that a covenant must conform to righteousness; if signed under duress, the spirits would not acknowledge it, and the covenant could be disregarded. Through his actions, Confucius illustrated the true meaning of the saying, "When trustworthiness is close to righteousness, one's words can be fulfilled."