רבי אלעזר בן ערך איקלע להתם אימשיך בתרייהו איעקר תלמודיה כי הדר אתא קם למיקרי בספרא בעא למיקרא החדש הזה לכם אמר החרש היה לבם בעו רבנן רחמי עליה והדר תלמודיה
I heard the following from my Zadie, R’ Chayim Yaakov Bulka, ז"ל:
In parshas Bo, (12:2) B'nei Yisrael are given their first mitzvah as a nation, the mitzvah of Kiddush HaChodesh. This mitzvah deals, in general, with the setting of our calendar. It vests in the Sanhedrin and those empowered by the Sanhedrin, the authority to intercalate months or years (i.e. determine the length of the month or the occurrence of a leap year). The complex calculations and procedures pertaining to intercalation are called "Sod haIbur." As the word "sod," secret, implies, this is part of the deeper realms of Torah.
The above gemara relates a story about the dangerously mystical powers of the wines of Prugaisa and waters of Diumsis. The great Rabbi Elazar ben Arach visited these wonders and was overcome and forgot his learning. When he returned, he got up to read the aforementioned pasuk. Instead of reading "HaChodesh hazeh lachem," this month shall be for you, he switched the dalet for a reish, the zayin for a yud, the chuf for a beis and misread, "hacheireish hayah libam," and their hearts were deafened and muted. The Rabbis prayed for him and he returned to his normal self. Nevertheless, it is quite shocking for such a notable sage to be overcome to such an extent. Is it possible that R' Elazar was so deeply influenced that he forgot how to read an elementary pasuk?
This mysterious performance of R' Elazar may, perhaps, be explained by referring to a beautiful explanation by the Gaon of Vilna. The pasuk (Yeshayah 6:10) says "Make the heart of the people fat, make their ears heavy and smear over their eyes; lest they see with their eyes and hear with their ears and understand with their heart and return..." The pasuk, referring to the sealing off of the path of repentance, starts off with the heart, then the ears and then the eyes but continues backwards from the eyes, then the ears then the heart.
The GR"A explains that eyes, ears and heart correspond respectively to Torah ShebiChsav, the Written Tradition, Torah SheBa'al Peh, the Oral Tradition, and Sodos HaTorah, the deep secrets of the Torah . The study of Torah ShebiChsav and Torah SheBa'al Peh, will ultimately lead to understanding of Sodos HaTorah. The neglect of Torah study will first deprive an understanding of Sodos HaTorah, to be followed by forgeting of Torah SheBa’al Peh and finally, even Torah ShebiChsav will no longer be comprehensible. However, if diligent and continuous study is resumed again, first the eyes will begin the study of the Written Tradition, followed by careful and concentrated attention with the ears to the Oral Tradition and, eventually, by persistent study, the heart will regain the ability to penetrate and comprehend the deep secrets of Torah.
We can assume that R’ Elazar ben Arach, the "ma'ayan hamisgabeir," (Avos 2:8) did not forget the Written and Oral traditions. However, by reading "Their hearts were deafened," he made a personal statement, a cry for help. This pasuk, "HaChodesh hazeh lachem," which commands us to put into practice the Sodos HaTorah, was now beyond his reach. By allowing himself to be drawn to the wines of Prugaisa and waters of Diumsis, his heart became deafened and no longer had the capacity to comprehend Sodos HaTorah, including Sod HaIbur. The rabbis answered his outcry and prayed for him and his mastery of Sodos HaTorah was returned to him.