No time before Shabbat comes in...
So here is a dvar Torah given by R. David Green, "The Power of Words", from the torah.org website. Shabbat Shalom.
Parshas Metzora deals with a skin condition which people at one time contracted as a result of speaking ill of others. Many people have difficulty relating to the idea that the Torah forbids negative speech about others. Often when cautioned about speaking negatively, people will react by saying "well, it's true!" Still, the Torah looks askance at such speech. The question is: why?
The Chofetz Chaim (Rabbi Yisroel Meir Kagan, d. 1933) offers a beautiful explanation in his book "Shmiras HaLoshon." King David in Psalms 34 says "Who is the man who desires life, loves days to see good? (My advice is) guard your tongue from evil, and your lips from deceit etc." Why does it say that life and goodness depend on proper speech? King David wants to convey to us the importance of concern for the well being of others. This means that people should be careful even about what they say of others, taking care not to harm anyone through something they say. Someone who is that careful will certainly develop a sensitivity not to DO an action which would cause harm to another person.
However, although this is true, it seems that speaking ill of others has an intrinsic negative side to it as well, aside from what it leads to. The Talmud Yerushalmi writes that the act of learning Torah is the greatest of all of the commandments, and corresponding to that, is that the transgression of speaking ill of others is the worst of sins. The Chofetz Chaim explains that the more spiritual a force is in the world, the stronger it is. His example is fire. It has an ability to consume most things more physical than it is. Wind is the second example he cites. Wind is less of a physical force, and it has the ability to destroy in a most profound way. Since speech involves air, it is a very spirtual force. When it is used positively, its effect is more profound than a positive act which takes on more physical trappings. The same is true in the converse. Negative speech has a more significant effect than a corresponding negative act on a more physical plane.
No one needs to be convinced of the problems people cause through negative speech. We probably all remember the time we wished we hadn't said something. Sensitivity in what we say is an important key to living a happy, effective life.
There is a famous analogy regarding the topic of speech. A man who was not particularly careful about his speech came to a Rabbi. He had decided to change, and needed advice on how to go about it. The Rabbi gave him a very peculiar answer. "Take a feather pillow into the street, and release its feathers in every direction." The man was perplexed, but his resolve was firm to do as he was advised and change his life. After doing as he was told he returned to the Rabbi. "Now what should I do?" he asked. "Go back into the street and collect all of the feathers to the very last one," was the astounding reply. Again the man made his way into the street and began the daunting task. At his wits end he returned to the Rabbi dejected reporting his inability to keep his last words of advice. "Remember," said the Rabbi, "that your words are like those feathers. Once they leave your mouth they never return. Make sure the words you allow out are ones you won't have to go chasing after!"