﴾Have you not considered how Allah presents an example, [making] a good word like a good tree, whose root is firmly fixed and its branches [high] in the sky?﴿ God stated in the Holy Quran.
The Islamic Laws called us to be endowed with good manners, and good sayings; it stressed on that too much to let the social peace spread in the society, and to strengthen the society's relationships.
God Almighty said:
﴾And tell My servants to say that which is best. Indeed, Satan induces [dissension] among them. Indeed Satan is ever, to mankind, a clear enemy﴿.
﴾And speak to people good [words]﴿
﴾And not equal are the good deed and the bad. Repel [evil] by that [deed] which is better; and thereupon the one whom between you and him is enmity [will become] as though he was a devoted friend.﴿
It was narrated that once a man came to Prophet Mohammad (peace be upon him and his household) and told him: “O Messenger of Allah, give me a commandment: the Prophet answered: preserve your tongue', Then the man said: give me a commandment'. The prophet answered again: 'preserve your tongue'. The man came back to ask him the same question, then the prophet repeated what he had recommended him previously “preserve your tongue”. O, on the day of resurrection, the ones who didn't preserve their tongues, and used to talk bad things and backbite others, will be thrown on their noses to the hell!!”
Moussa bin Jaafar narrated about his dad about his fathers the following: “May God has mercy upon the one who had said good sayings, in which he will be rewarded, and if he kept silent from saying bad things, then he will be secured.”
In fact, we find out from the addressed texts the importance of clinging to good saying, and preserving our sayings from obscenity ones. We should try to let our tongue to get accustomed to good and pleasant sayings.
Hence, the pure and noble sayings will influence in both the friends' and the enemies' souls. It will make love grow more in the friends, endure the cordiality, and prevent the insinuations of the Devil from foiling the friendship relations and cordiality.
On the other side, the good sayings will soften the enemies' feelings and lessen their offense and deceit.
Nothing is easier for the person's stupidity and folly from chatter, other than curiosity and obscenity of talking.
The Commander of the Faithful (A.S.) passed once by a curious man who was talking things that are not for his interest, then Imam (A.S.) stood and told him: 'O man, you are dictating things about people who had kept it as a secret, so say things that are in your interest and stop on saying things that are others' interests'.
Imam Ali (A.S.) said: ‘he who talks a lot, will be doing lots of mistakes, and he whose mistakes increase, his shyness will decrease, and he whose shyness decreases, then his piety will decrease. And the one whose piety decreases, then his heart will die, and the one whose heart dies, will enter to the hell'.
It was said about Soulaiman Bin Mahran the following: 'I went to Imam Al-Sadiq (A.S.) one time, he was sitting with a group of Shiah people, so I heard him saying: "O Shiah, be our representatives, be good ones, and don't dishonour us, behave well with people and tell them good things, and protect your tongues from any bad saying. Don't be curious ones and say things about others".
Imam Zayn Al-Abedien (A.S.) said: "the right of your tongue to honour it from any stink, let it be accustomed to say good and pleasant things, and let it quit from saying things that aren't in your interest and to be pious".
Eventually, all praise is due to Allah, the Lord of the worlds.