Safeguarding the Tongue
by Maulana Ashraf Ali Thanwi
Translated by Moulana M. Mahomedy.
1. Do not speak without thinking. Once you have pondered over what you wish to say and you are convinced that it will not be badly received, only then should you speak.
2. It is a sin to address a person or speak of him in the following terms: "he has no Imaan", "may Allah's punishment, curse, or anger descend on him", "may he enter hell", etc. It is a sin to speak in this manner irrespective whether one is addressing a human or an animal. If the person who has been addressed in this manner does not deserve such remarks, then all these curses will actully descend on the person who uttered them.
3. If anyone addresses you in this useless manner, you have the right to reply in the same way. However, you cannot exceed what that person says. If you exceed, you will be committing a sin.
4. Do not be two-faced whereby you "play according to the tune" of one person when you are in his company, and according to the "tune" of another person when in the latter's company.
5. Don't ever back-bite. Nor should you listen to such back-biting and tale-bearing.
6. Never ever speak a lie.
7. Do not praise a person directly. Nor should you exaggerate in praising him in his absence.
8. Don't ever involve yourself in gheebah. Gheebah means speaking in the absence of a person in such a way that if he were to hear it, he would be grieved. This is irrespective of whether what you say is the truth or not. If what you say is false, it is regarded as slander or defamation. This is even more sinful.
9. Do not argue with a person. Do not try to give precedence to your opinion.
10. Do not laugh excessively as this causes the illumination of the heart (and countenance) to disappear.
11. If you have made gheebah of a person, seek his forgiveness. If you are unable to do so, make dua-e-maghfirah on his behalf. In doing this, there is a hope that you will be forgiven on the day of judgement.
12. Do not make false promises.
13. Do not laugh in such a way that the other person feels insulted or offended. (In other words, do not laugh mockingly at anyone)
14. Do not be boastful of something that you own or some quality that you possess.
15. Do not mention things that you hear from here and there because the majority of such rumours are false.Source
Anger Management in Islam