The story you narrated explained this topic very well. When a king told that he will marry his daughter to that person who will fulfil his two conditions. When poor man fulfiled his first and then second condition king was impressed from. The two conditions sweet and the bitter is what a person with the help of his tongue speaks.
If you want to be successful in life just learn how to have a control on your tongue. Let your tongue always be sweeter with everyone.
The famous Telugu poet, Tenali Ramalinga Kavi is very famous for his tongue usage. One day Dhoorjati in Sri Krishnadevaraya's kingdom gave a puzzle to make a poem which is meaningful. The puzzle is an elephant entered into the trunk of the mosquito. Immediately Ramalinga Kavi completed poem which means, that are you a fool or did you take alcohol. How you expect an elephant into the trunk of a mosquito. Nobody can say anything as it is a free reply but not addressed anybody. But the king got annoyed and said that I am giving you the same puzzle, answer it differently otherwise you will be sent off this court. Then Ramalinga Kavi completed another poem which means, Oh, what a mystery of life. Pandavas were very good kings and with a big Kingdom whereas Virat Raju was a small king with a small kingdom. But the fate can't be changed. Pandavas had to spend one year in Virat's court as his helpers. This is nothing but an elephant entering into a mosquito's trunk. The king was very happy and gave one lakh rupees as a gift. That is the power of tongue,
While we talk about tongues, maintaining secrets and sensitive information carefully needs to be highlighted. There is a well known slogan from World War II 'Loose tongues, Lose ships'. This was used as a slogan by the postal department and in places frequented by the armed forces for recreation. This was to remind that a careless gossip about sensitive information leaking out to enemies easily.
Many experts advise to have mental filters, if we have to speak some words in a heated argument or a discussion, first to think, Do I need to say it? What would be the impact on the other person? Would I accept the same if someone were to tell me the same words?