Say about others what you would want said about yourself!
Why is the Parsha of ‘negaim’ (tzaraat – skin afflictions that are specific types of discolorations which occurred sometimes as a result of gossip/slander – lashon hara) immediately after the Parsha of ‘ma’achalot asurot‘ (forbidden foods – the end of Parshat Shmini which deals with kosher and non kosher species )?
The Baalei Mussar (Morality Movement) explain that this is to teach us that it is not enough to be careful with what we put into our mouths, that it should be kosher, but also with what comes out of our mouths should also be clean and kosher.
The need to stop speaking lashon hara can be neatly summed up in a proverb attributed to Rabbi Yisrael Salanter, the famous founder of the Mussar Movement He said: “Jews must be as careful about what comes out of their mouths as about the food that goes into their mouths”.
When people speak lashon hara they spill the blood of their Fellowman and commit character assassination with less concern than when they avoid forbidden foods. Indeed, our Fellowman should be included in the list of animals forbidden to eat!
Good advice to follow is to say about others what you would want said about yourself.