ויקרא, פרק ט״ו, פסוק ג׳

The laws governing the impurity of a man experiencing an unnatural bodily discharge depend entirely on the physical nature of the fluid and the frequency of its appearance. The primary approach among commentators is that there are two distinct physical states of this discharge. The first is a thin, runny fluid that drips continuously and passively on its own [רש״י, רשב״ם, אבן עזרא, המלבי״ם, שטיינזלץ, ביאור יש״ר, רש״ר הירש], distinguishing it from fluids like saliva which are forcefully expelled from the body [תורה תמימה, המלבי״ם, אילת השחר, פרדס יוסף]. The second state is a thicker, viscous discharge that congeals and blocks the bodily opening [רש״י, רשב״ם, אבן עזרא, המלבי״ם, שטיינזלץ, ביאור יש״ר]. Even if this thicker fluid simply dries at the opening without fully exiting the body, it still triggers impurity [העמק דבר]. Regardless of whether the fluid is thin and runny or thick and blocking, the resulting level of impurity remains exactly the same [ביאור יש״ר, רד״צ הופמן].

Beyond its physical characteristics, the law outlines a strict progression of impurity based on how many times the discharge occurs. Unlike a woman, whose impurity is determined by the number of days she experiences bleeding, a man's impurity is dictated solely by the number of times the discharge appears. This holds true even if multiple appearances happen on the exact same day or form one long, continuous flow [רלב״ג, תורה תמימה, המלבי״ם, רש״ר הירש, רד״צ הופמן, בכור שור]. The legal progression unfolds in three stages. A single appearance brings about a light impurity, similar to a standard seminal emission [שפתי חכמים, רלב״ג, בכור שור, רד״צ הופמן]. A second appearance elevates his status to a full state of severe impurity, meaning he now transfers impurity to any object he sits or lies upon, and he must count seven clean days before he can become pure [רש״י, הרא״ם, שפתי חכמים, תורה תמימה, בכור שור, ברטנורא, רד״צ הופמן]. A third appearance adds a final layer of severity, requiring him to bring a sacrifice at the conclusion of his purification process [רש״י, הרא״ם, שפתי חכמים, תורה תמימה, בכור שור, ברטנורא, רד״צ הופמן].

The precise definitions of this condition also establish exactly which fluids transmit impurity. Because a man's urine inevitably mixes with traces of the discharge, it also becomes impure. In contrast, other bodily fluids such as tears, blood, and breast milk do not carry this severe impurity [תורה תמימה, המלבי״ם, אדרת אליהו]. Furthermore, this specific type of impurity is entirely unique to men and is caused exclusively by a white discharge [אור החיים, תורה תמימה, אדרת אליהו], whereas a woman's impurity is brought about by blood [אור החיים, תורה תמימה, המלבי״ם]. Regarding the exact volume of fluid required to render a man impure, commentators differ. Some maintain that the minimum amount must be large enough to block the bodily opening, while others argue that any amount, even the smallest drop, is sufficient to cause impurity [בכור שור, אדרת אליהו, תורה תמימה].