There are several versions of an old Jewish joke about a revered rabbi, the leader of one of the great Hasidic dynasties who passes on and is welcomed to the World to Come.

“Rav, we have been expecting you,” said the greeter of Gan Eden. “All of the great leaders, sages, prophets and other great rabbis are eager to welcome you at a heavenly banquet in your honor. “That’s wonderful,” said the rabbi, but I have to ask, what is on the menu?” “For you, Rav, we have glatt kosher nectar of the hosts of heaven and ambrosia.” “Again, wonderful,” said the rabbi.

“But I must ask, who is the meshgiach so I can be absolutely sure it is truly glatt kosher?” “For you, Rav, only the Eternal is qualified to perform that task.” “Thank you,” said the rabbi. “I think I’ll have the fruit plate.”

The good-natured joke paraphrased above reflects the age-old struggle by the religiously observant Jews to follow the 613 mitzvot, or commandments contained in the Torah as meticulously as possible.

No matter how strict one group might be in its observance, there always seem to be Jews who are “more frum than thou.”

A. J. Jacobs, editor-at-large of Esquire, and author of the New York Times best-seller Know It All, about his quest to read the entire multi-volume set of the Encyclopedia Britannica, has used a similar discipline in his widely acclaimed current book, The Year of Living Biblically: One Man’s Humble Quest to Follow the Bible as Literally as Possible.

In preparing for Know It All, Jacobs subjected his mind to the rigors of reading each and every entry of every volume of the most comprehensive encyclopedia in history.

One would have to go back to the awe-inspiring feats of Elijah, the Vilna Gaon, who not only read, but mastered the entire Bible and Talmud and could recite much of it by heart, to find a predecessor as dedicated as Jacobs has been in this post-modern world to subject himself not only to the reading of the Encyclopedia Britannica, but to spend another entire year of his life attempting to conduct himself in total harmony with each and every requirement enunciated in the Bible.

The result of both quests are two highly-readable and compelling books. The Year of Living Biblically is one of the featured books at the 2007 St. Louis Jewish Book Festival, and Jacobs will give a talk on his work at 1 p.m., Monday, Nov. 5 at the Jewish Community Center.

In the course of his challenging year, Jacobs even went beyond the 613 mitzvot, or commandments counted by Maimonides in the Torah or the Five Books of Moses.

In addition to the Tanakh, the Hebrew Bible, Jacobs researched numerous other translations of the Bible, coming up with a list of more than 700 rules he vowed to obey for a solid year. The rules included not only the “Big Ten” Commandments, but such mitzvot as not wearing clothing of mixed fiber. He made a conscious effort to honor his parents and to authentically love his neighbors.

He would “remember the Sabbath” and “keep it holy.” He did not shave the sides of his head, and refrained from wearing women’s clothing. He also made a valiant effort not to lie — even white lies. In addition, he vowed not to covet, engage in loshen hara or gossip or touch anything deemed unclean, for a full calendar year.

What makes Jacobs’s incredible year all the more impressive is that he is not an especially observant Jew to begin with, having a theology that is closer to agnostic than theistic. Among the amusing aspects of his journey was an encounter in his apartment with a Jehovah’s Witness. They “met for hours discussing religion, until the Witness finally said, ‘Okay, that’s enough!”

Jacobs is a researcher and writer who takes his time before he says, “Okay, that’s enough!” He kept on reading volume after volume of the Encyclopedia Britannica until he could say that he was the first single person known to have read each word of the massive compendium of knowledge. And he expended all of his energies for a full year attempting to observe all of the commandments enumerated in Scripture. What was challenging for him is a treat for his readers, and his talk promises to be filled with interesting anecdotes from his Year of Living Biblically.

A.J. JACOBS, author of “The Year of Living Biblically,” published by Simon & Schuster, N.Y., will speak at 1 p.m. on Monday, Nov. 5.

Admission: $12 or free with festival series ticket