Only in Israel
What is the root cause for the disease of tzara'at as described in the Torah? The Midrash explains that this skin disease is a punishment for gossip and slander. A person suffering from tzara'at is called a metzora because he is motzee sheim ra — he spreads derogatory reports [Vayikra Rabbah 16:1. See Rambam, Hilchot Tzara'at 16:15, that one fulfills the mitzvah "Be careful regarding tzara'at" [Deut. 24:8-9] by avoiding gossip].
Given that tzara'at is brought about by slander, one would expect that all peoples would be afflicted, since even non-Jews are culpable for personal damages. Yet, Maimonides wrote that tzara'at is not a natural phenomenon, but a unique sign found only among the people of Israel. Why should only the Jewish people suffer from this ailment?
There are two levels of speech. There is everyday speech, based on and limited to that which occurs in the physical universe. And there is a higher form of speech, a holy speech that God bestowed to Israel. This elevated speech does not come from the world. On the contrary, the world comes from it. This is the speech by which God created the world. "By the word of God, the heavens were made; and by the breath of His mouth, all of their host" [Psalms 33:6].
God granted us the power of His speech, this speech that preceded the world, when He gave us the Torah, the blueprint of creation. "He looked in the Torah and created the universe" [Zohar Terumah 161b]. The transmission of Divine speech to the Jewish people is hinted in the verse, "I put my speech in your mouth... to plant the heavens and lay the foundations of the earth" [Isaiah 51:16].
Redemption of Speech
The Kabbalists explained that the Hebrew name for Passover, Pesach, is a combination of the words peh sach — 'the mouth speaks.' The redemption from Egypt, which paved the way for the Torah's revelation at Sinai, also redeemed the faculty of speech. For this reason, Passover is commemorated with an oral mitzvah, the mitzvah to retell the story of the Exodus. And we find that Moses, aware of this aspect of the redemption from Egypt, tried to disqualify himself by protesting, "I am not a man of speech" [Ex. 4:10].
In an essay entitled ' The Redemption of Speech,' Rav Kook wrote: "Sometimes we can sense the connection between our speech and the universe. This is the initial step to redeem speech from its exile."
"As the soul is elevated, we become acutely aware of the tremendous power that lies in our faculty of speech. We recognize clearly the tremendous significance of each utterance; the value of our prayers and blessings, the value of our Torah study, and of all of our discourse. We learn to perceive the overall impact of speech. We sense the change and great stirring of the world that is caused by speech." [Orot HaKodesh vol III, p. 285]
The most striking expression of the difference between these two levels of speech is the remarkable statement of Rabbi Shimon Bar-Yochai: "Had I been present at Mount Sinai, I would have requested that God create us with two mouths. One mouth to speak in words of Torah, and one mouth for all of our mundane needs." [Jerusalem Talmud Berachot 1:2]
We may lack a mouth specially dedicated to Torah and prayer, but we can still deepen our awareness of the extraordinary nature of holy speech. At the start of the morning prayers, we recite a wonderful kavanah: "I hereby prepare my mouth to thank and praise my Creator." With this short declaration, we prepare ourselves to employ our mouth for a totally different form of speech. We prepare ourselves to use the sublime speech that is rooted in the source of Divine wisdom. Since this discourse comes from the elevated speech used to create the universe, our prayers have the ability to influence the world and change its course [Olat Re'iyah vol. I, p. 192].
With this appreciation for the power of holy speech, we may understand why tzara'at only afflicts the Jewish people. Our faculty of speech, based on the Divine speech that transcends the universe, can influence the world for good and for bad. When we misuse this great power, we damage the world and are held responsible. The affliction of tzara'at — and the process of purifying oneself from it — comes to repair this wrong. The verbal communication of other nations, however, comes from within the physical universe. Since it lacks the power of elevated speech, they are not punished for its misuse. [Adapted from Mo'adei HaRe'iyah, pp. 295-296]Source: Rav Kook Torah