言而必有信，期而必当，天下之高行也。
【大意】说话一定要讲信用，约定了就一定要做到，这是天下的高尚行为。
You are too generous to trifle with me. If your feelings are still what they were last April, tell me so at once. My affections and wishes are unchanged, but one word from you will silence me on this subject forever.
信任是每一段牢固关系的基础，无论是与员工、合作伙伴还是客户。