When a glass is broken, the sound of breaking disappears immediately whereas the glass pieces are scattered all over the ground hurting whoever walks over it. Similarly, when you say something that hurts people's emotions and feelings, the voice disappears in no time but the hearts feel pain for long.Therefore, don’t say except good and remember always the nine advises and prohibitions that Allah Almighty gave us in Surah Al Hujuraat (The Surah of Islamic Manners) before you say something to anyone:
1. “Fa tabyyanu”: Investigate, if you receive an information lest you harm people out of ignorance.
2. “Fa aslihu”: Strive for settlement between your brothers as believers are brothers.
3. “Wa aqsitu”: Act justly, whenever there is a dispute, try for settlement and act justly among both parties as Allah loves who acts justly.
4. “La yaskhar”: don’t ridicule people, they may be better than you in the sight of Allah.
5. “Wa la talmizu”: Do not insult one another.
6. “Wa la tanabazu”: Do not call each other with offensive nicknames.
7. “Ijtanibu katheeran min al-zann”: aviod negative assumptions; indeed some of the assumptions are sin.
8. “Wa la tajassasu” and don’t spy on each other.
9. “Wa La Yaghtab”: Do not backbite each other. It is a major sin and tantamount to eating your dead brother’s flesh.