history - What is Ezra's Immersion / טבילת עזרא

What is Ezra's Immersion / טבילת עזרא and:

1. Why was it canceled?


2. How was it canceled?

Answer

I found the following in Rambam's Mishneh Torah:

ספר אהבה הִלְכּוֹת תְּפִלָּה פֵּרֶק ד

ד כָּל הַטְּמֵאִים--רוֹחֲצִין יְדֵיהֶן בִּלְבָד כַּטְּהוֹרִין, וּמִתְפַּלְּלִין: אַף עַל פִּי שֶׁאִפְשָׁר לָהֶן לִטְבֹּל וְלַעֲלוֹת מִטֻּמְאָתָן, אֵין הַטְּבִילָה מְעַכֶּבֶת. וּכְבָר בֵּאַרְנוּ שֶׁעֶזְרָא תִּקַּן שֶׁלֹּא יִקְרָא בַּעַל קֶרִי בִּלְבָד דִּבְרֵי תּוֹרָה, עַד שֶׁיִּטְבֹּל. וּבֵית דִּין שֶׁעָמְדוּ אַחֲרֵי כֵן, הִתְקִינוּ אַף לַתְּפִלָּה, שֶׁלֹּא יִתְפַּלַּל בַּעַל קֶרִי בִּלְבָד, עַד שֶׁיִּטְבֹּל. וְלֹא מִפְּנֵי טֻמְאָה וְטַהְרָה נָגְעוּ בָּהּ, אֵלָא כְּדֵי שֶׁלֹּא יִהְיוּ תַּלְמִידֵי חֲכָמִים מְצוּיִין אֵצֶל נְשׁוֹתֵיהֶן כְּתֻרְנְגוֹלִין; וּמִפְּנֵי זֶה תִּקְּנוּ טְבִילָה לְבַעַל קֶרִי לְבַדּוֹ, וְהוֹצִיאוּהוּ מִכְּלָל הַטְּמֵאִים.

ה לְפִיכָּךְ הָיוּ אוֹמְרִין בִּזְמָן תַּקָּנָה זוֹ, שֶׁאַפִלּוּ זָב שֶׁרָאָה קֶרִי וְנִדָּה שֶׁפָּלְטָה שִׁכְבַת זֶרַע וְהַמְּשַׁמֶּשֶׁת שֶׁרָאָת נִדָּה, צְרִיכִין טְבִילָה לְקִרְיַת שְׁמַע וְכֵן לִתְפִלָּה מִפְּנֵי הַקֶּרִי, אַף עַל פִּי שְׁהֶן טְמֵאִין. וְכֵן הַדִּין נוֹתֵן, שְׁאֵין טְבִילָה זוֹ מִפְּנֵי הַטַּהְרָה, אֵלָא מִפְּנֵי הַגְּזֵרָה, שֶׁלֹּא יִהְיוּ מְצוּיִין אֵצֶל נְשׁוֹתֵיהֶן תָּמִיד. וּכְבָר בָּטְלָה גַּם תַּקָּנָה זוֹ שֶׁלַּתְּפִלָּה, לְפִי שֶׁלֹּא פָשְׁטָה בְּכָל יִשְׂרָאֵל, וְלֹא הָיָה כּוֹחַ בַּצִּבּוּר לַעֲמֹד בָּהּ.

A very quick, rough translation:

All the impure wash their hands like the pure and pray: even though it's possible for them to immerse and remove their impurity, it doesn't prevent praying. And we already expounded on that Ezra made an enactment such that anyone who has had a seminal emission should not read words of Torah until he has immersed. And the courts which stood after that time enacted this also for prayer, that someone who has had a seminal emission should not pray until he has immersed. And this not due to issues of purity or impurity, but such that Torah Scholars should not be busy with their wives all the time in the way roosters; and because of this immersion was enforced after a seminal emission alone, as opposed to other impurities.

Accordingly, at the time the enactment was in force, that even a zav who had a seminal emission and a niddah who had a seminal emission and a woman who copulates and see's that she's become niddah, they require immersion prior to reciting the Shema prayer or regular prayers due to the emission, even though they are impure. And we see that this immersion is not for purities sake, but due to the enactment, such that they should not constantly be with their wives. And also even this enactment regarding prayer has been canceled, since it did not spread to all of Israel, and the public didn't have the strength to abide by it.

EDIT

Just ran across this very detailed article on the subject from the Virtual Beit Midrash in Har Etzion. If I have a chance maybe I'll translate parts of it and post it here.