" In Parasha B'reisheet (Genesis 1:1-6:8), we learn many important lessons, but none more powerful and enduring than the significance and holiness of words and speech. The Torah teaches us that YHVH created the world through ten utterances: through Divine speech. With each holy command, our universe was formed. YHVH implanted this gift of speech within man. Of all earth's creatures, only humans are endowed with the ability to verbally communicate intelligently. We must be ever mindful that, even as Elohim created through "words", on our own level, we too create through words.
Time and again, the Torah cautions us to be very careful with that which escapes our lips, for, as King Solomon tells us, "Death and life are in the tongue." Before speaking, stop for a moment and consider how your words impact on others. What sort of environment and relationships do you create with your speech? Do you speak to your family and friends with love and respect? Do you think about what you're saying before you say it and the effect that it will have on those with whom you communicate? How careful are you with that which escapes from your lips?
There are more commandments in the Torah in regard to speech than to any other mitzvah: seventeen negative and fourteen positive mitzvos. It is through speech that we signaled our committment to our Covenant at Sinai when we proclaimed, "Na'aseh V'nishma - We shall do it and we shall study it." It is through speech - prayer - that we speak to Elohim on a daily basis, bringing a positive spiritual influence into the mundane. Yet speech can have terribly negative effects as well: It was through speech that Hitler committed the most unspeakable evil ever to be perpetrated upon mankind. He himself never lifted a weapon; he used his lethal tongue to incite the world to hatred and slaughter. Indeed, "Death and live are in the tongue."
Think before you speak and ask yourself, "Will my words generate light or darkness, love or hatred, blessing or curse?" The choice is your to make. Use your Divine gift of speech carefully and wisely, in the service of the Almighty. "
- Torah for Your Table - Rabbi Yisroel and Osher Anshel Jungreis