Paradoxically, tzara’at on a person’s skin renders him ritually defiled only if it covers part of his body. If it spreads over his whole body, he is not ritually defiled.
A Light Unto the Nations
וְהִנֵּה כִסְּתָה הַצָּרַעַת אֶת כָּל בְּשָׂרוֹ וְטִהַר וגו': (ויקרא יג:יג)
If the tzara’at has covered all his flesh, he is not defiled. Leviticus 13:13

One of the signs given by the sages that the Messiah’s arrival is imminent is that “the government has become heretical.” This notion is alluded to in the law that if tzara’at covers the entire body, the person is not defiled.

There are two ways that the world’s governments can be considered to have become “heretical.” The negative way is for heresy to indeed infect all the world’s governments. The positive way is for the truth of the Torah to become so self-evident that it will be universally acknowledged that any government that does not submit to the Torah’s rules is “heretical.”

It is our hope and prayer that redemption occur the second way. It is therefore imperative that the Jewish people encourage the nations of the world to fulfill the commandments that the Torah obligates them to observe. By acknowledging the Torah as the sole possible basis for true ethical behavior and moral justice, the non-Jewish world will come to recognize and appreciate the Jewish people as the vanguards of universal justice, morality, and peace. This will pave the way for the ultimate, Messianic Redemption.1