"Avtalyon says: Scholars, be cautious with your words, for you may incur the penalty of exile and be banished to a place of putrid water…." (Avot 1:11)
While a simple reading implies that the Torah scholar will be exiled, it is also possible that the phrase "that you may incur the penalty of exile" refers to the immediately preceding antecedent "your words".
As long as the Jewish people were exiled, G‑d's most intimate form of speech…was inaccessible….
How can words be exiled? To appreciate this concept, we recall the renowned statement of the Zohar (Vaeira 25b) that the Divine Word (dibur) went into exile during the period of Egyptian slavery and was not totally liberated until the Giving of the Torah when G‑d spoke directly to every Jew (as in the phrase "vayedaber Havaya").
As long as the Jewish people were exiled, G‑d's most intimate form of speech, known as "dibur", was inaccessible to the vast majority of the Jewish nation. Only in the unique atmosphere of Sinai, when Israel had achieved spiritual as well as physical freedom, could G‑d speak again, with the intimacy and clarity of "dibur".
In the same vein, the Mishna is admonishing the Torah scholar to weigh carefully every word, since he may be living in an era in which the words of Torah are in exile, i.e. easily misunderstood. While in previous generations a scholar could presume that his audience would appreciate and comprehend his words, that assumption is no longer necessarily true.
[Anthologized and adapted by Yosef Stern in "Pirkei Avos - With Ideas and Insights of the Sfas Emes and other Chassidic Masters"(Mesorah Publications, ltd)]