ויקרא, פרק י״ג, פסוק ל״ג

When an individual is examined for a suspected affliction on the head or beard and the condition remains unchanged after an initial week of isolation, a precise shaving process is required before entering a second week of quarantine. The wait for a second week is necessary because the affliction rarely spreads during the first week. However, as the second week approaches, the likelihood of the condition expanding increases, demanding much closer and more accurate monitoring [העמק דבר].

The specific requirement to shave at this stage is unique and differs significantly from the final shaving performed during the purification process. First, the shaving does not have to be performed by a priest; the individual or anyone else may do it. Second, any method of hair removal, such as scissors or a special depilatory agent, is acceptable, and a razor is not strictly required. Finally, this action is an absolute obligation that overrides other prohibitions. Therefore, even a Nazirite, who is normally under a strict ban against cutting hair, is completely obligated to shave for this procedure [תורה תמימה, מלבי״ם, ביאור ישר, רד״צ הופמן, חזקוני].

A logical question arises regarding the instruction not to shave the afflicted area itself. Since the affliction is essentially a bald spot where hair has already fallen out, it seems impossible to shave an area with no hair. Commentators offer two complementary perspectives to resolve this. The first approach focuses on the bald skin itself. Passing a razor over the bare skin is forbidden because scratching the surface could stimulate artificial hair growth, which would interfere with an accurate diagnosis [רמב״ן]. Furthermore, if any yellow hairs remain inside the bald spot to act as a sign of impurity, it is strictly forbidden to shave or pluck them, as doing so would conceal the evidence of the disease [תורה תמימה, מלבי״ם, רד״צ הופמן].

The primary approach among commentators views the instruction as focusing not on the bald spot itself, but on its immediate borders. The individual must shave all the hair surrounding the affliction while leaving a narrow border, just two hairs wide, directly adjacent to the bald spot on all sides [רש״י, רמב״ן, מלבי״ם, ברטנורא]. Leaving these specific hairs provides the priest with a clear boundary line to monitor for any spreading. If the bald spot expands, it will either cause these adjacent hairs to fall out or breach the boundary into the newly shaved area, clearly proving the affliction has spread [רש״י, חזקוני, בכור שור, משכיל לדוד]. From this requirement, it is understood that this specific type of affliction is characterized primarily by hair loss rather than a noticeable change in skin color. If the skin color were clearly altered, there would be no need for a border of hair to track its expansion [רש״ר הירש].

Following this precise preparation, the priest places the individual in a second seven-day quarantine, returning them to an intermediate state of waiting [ביאור שטיינזלץ]. The duration of seven days is chosen because it represents a significant natural cycle, corresponding to a quarter of the lunar month. This specific timeframe allows enough physiological and natural changes to occur within the human body and the affliction itself, ultimately enabling the priest to reach a clear and final decision [רלב״ג].