Brachot 22 - Words of Torah do not Become Impure
If one who had a seminal emission does not have a mikveh available to him, he can prepare a vessel with nine "kavin" - about nine liters of water - an pore it over himself, and he will be pure to read the Shema and study the Torah.
The discussion about the "immersion of Ezra" continued both in the time of the Mishnah and in the time of the Talmud. Who was it for, for a healthy person or even for a somewhat weak one? Was it for the one who had accidental emission, or also for one who experienced it at will, as a result of his marital relations? Also, the nine kavin vessel above, who was that for? - which combination of the factors allowed or even required it?
Finally, even though some individuals continued to practice it, the custom has become not to require the additional purification in the mikveh, following the opinion of Rabbi Yehudah ben Beteira. Here is how we know it. One student (who had an emission) was reciting Torah teachings in front of Rabbi Yehudah and was stammering. Rabbi Yehudah told him, "My son! Open your mouth and let your words shine forth!" As Jeremeiah said, "Behold, My words are like fire, says God." Just as fire cannot contract impurity, so words of Torah cannot contract impurity.
Art: Antonio Rotta - Student Dreamer