Every so often I encounter a book that gives me so much pleasure that I buy it in bulk and pass it out to my friends as presents. The last one was Joann Sfar’s The Rabbi’s Cat — a graphic novel exploring the inner life of a cat owned by the daughter of a Tunisian rabbi during the period of French colonial administration. Well, I’m happy to announce that I’ve struck paydirt yet again. If hol hamoed Pesach gives you any time to flop into your comfy La-Z-Boy for a good read, let me recommend as your literary companion Rabbi Martin Samuel Cohen’s The Boy on the Door on the Ox, subtitled “An Unusual Spiritual Journey Through the Strangest Jewish Texts” (Aviv Press, 2008).
The “strangest Jewish texts” of the subtitle are none other than the 12 tractates of the Mishna’s Order of Purities (Seder Tohorot). The boy on the door on the ox of the title is part of Mishna Tractate Parah’s depiction of the lengths to which the participants in the biblical Rite of the Red Heifer are preserved in a state of physical isolation from corpses so they may ensure the production of a purifying detergent made of the ashes of a red cow and water. The boy who draws the water, raised since infancy in a Temple apartment isolated from all possible impurity, sits upon a door tied to the back of an ox as he’s conveyed to the pool of Shiloach to draw water into stone vessels for use in the ceremony. The whys, wherefores, and so whats are expertly described in Cohen’s remarkable prose.
The “spiritual journey” upon which Rabbi Cohen invites his readers is a hike through the Mishna’s laws of purity, one of the most arcane topics of the halachic system of the early Sages. The laws govern how people, foods, and useful everyday objects — like stoves, ovens, cattle prods, Hawaiian shirts (okay, Sidonian togas), and sieves — contract a form of spiritual contagion from corpses, menstruants, parturients, gonorrheacs, and those suffering a rash rather more troublesome than “the heartbreak of psoriasis.”
Were the Temple in existence and the system of ritual purification fully operative, rabbinic law would oblige us to submit to a variety of regimes of purification that might include anything from a simple dip in a baptismal pool to the slaughtering of birds and herding beasts in a rite concluding one’s period of contamination.
The value of Rabbi Cohen’s book for readers other than those researching rabbinic arcana lies in his magical ability to turn the most obscure (and, it must be said, at times unappetizing) halachic problems into a platform for launching flights of literary artistry and religious insight of the most unsuspected kinds. He finds in the dankest corners of halachic curiosity — such as the ancient notion, adopted by the rabbis by way of Galen, that male semen is produced in the brain — food for thought that nourishes the most daring insights into the nature of life in a world constantly suffering the assaults of death, disease, and genital discharges as the constant existential challenges to the Jewish vision of humanity created in the image of God.
Each of Rabbi Cohen’s 12 chapters is devoted to an anonymous “spiritual guide,” whom he discerns hiding in the shadows of an obscure Mishnaic legal dilemma, silently pointing by his or her mute presence to the larger lesson about the life of the spirit that the Mishna’s Order of Purities has conjured that very soul to embody. For example, consider the scullery maid who is nursing her newborn while tending to a stew she is about to serve to a wedding party. A drop of milk drips from her breast into the stew. Rabbi Cohen explores the legal issues of this hypothetical threat, then takes us through the relevant opinions of Maimonides and other luminaries of the halachic tradition on the way to a homily on tumah (“uncleanness”) that simply cannot be paraphrased. So I offer about half of it here:

More than anything, the image that results is one of a planet on the brink. Of a world precariously balanced between good and evil, between purity and tumah, between the city of Yes and the city of No. Evil, mostly, is visible. But impurity is wholly invisible and mostly undetectable. The metaphysical balance of the world could reasonably depend on a single droplet of milk unintentionally expressed from the breast of a woman who may not even have noticed its furtive escape, much less be in a position to fathom the way the halachic status of the world all around alters in the course of its brief trajectory. In the rabbinic view, tumah is neither light nor darkness, but rather endless shadow — and not even shadow, not really, but rather the ever-shifting universe of shadow, echo, and memory that serves most people as the context for their deepest foreboding about the true nature of things” (p. 174).

Novices in rabbinic thought may find passages like the above tough going. So will the many experts in halachic literature who do not appreciate either the wonder of philosophy or the music of poetry. Those readers who see Judaism as “a religion of pots and pans,” however, will find The Boy on the Door on the Ox a revelation, for it reminds us that the purity of those pots and pans is the humble basis for the most breathtaking insights of the Jewish mind.
As I immerse my own family’s pots and pans in the boiling waters of the communal kashering vat on the days just before Pesach, I will be haunted in the most pleasant ways by the spiritual guides disclosed to us by Rabbi Cohen.

Award-winning columnist Martin Jaffee is the Samuel and Althea Stroum Professor of Jewish Studies at the University of Washington. When not masquerading as a journalist, he writes on the history of Talmudic literature as well as theoretical problems in the study of religion.