This article traces the evolution of a kabbalistic prayer supplication that was designed to purify male Jews from pollution caused by improper seminal emission. In doing so, it focuses on the metaphysical rationale behind it, its function, and its metamorphosis from a highly technical practice into a mainstream devotional practice. It addresses how notions of sexual pollution (qeri) were contextualized in Lurianic Kabbalah and how they were later embedded in kabbalistic manuals and prayer books. Furthermore, the article examines Jewish-Christian and inner- Jewish debates that emerged in connection with the effects of spilling semen in vain. Special attention is paid to possible social factors that may have impacted the increased anxiety about male bodily fluids and “misguided” desires. In addition to the available research on the theological and general historical background of the prohibition of wasting seed, the following analysis offers a microhistory of this short yet highly influential text.
