There is a saying: establish words as evidence. Explain the importance of text signature. Only when written evidence is established and can be verified can it be credible and counted. What has been said on the side cannot be used as evidence to restrain others without evidence. What I have said cannot be determined legally without other evidence to support it. If I don't admit it, it may really not count. But from a moral perspective, what you said does not count as it is not very moral. The moral aspect requires us to be responsible for what we have said and do what we say. A gentleman's words are hard to follow. However, it is one situation when you speak, and another situation after that. It is unrealistic to require everyone to keep their words. It also illustrates the importance of not trusting others and leaving evidence.