Or HaChaim on Leviticus 15:3/אור החיים על ויקרא ט״ו:ג׳

1 טומאתו בזובו, his impurity in his issue, etc. According to Torat Kohanim the sequence of these words mean that only the whitish coloured discharge transmits impurity as distinct from a reddish, blood-coloured discharge. The meaning is that but for the restrictive letter ב in the word בזובו, a discharge of blood would have been considered as conferring impurity even if the Torah had written the word זובו טמא הוא as it did in verse 2, we would have had to rule that a discharge of blood is also conferring ritual impurity. In other words, the restrictive expression we discussed at length in verse 2 would not have sufficed. The reason would have been that the expression זובו was used by the Torah in both verses. We would have been forced to conclude that the restrictive nature of the word זובו referred only to the afflicted person himself and not to his discharge. I would then have learned the קל וחומר from the הלכה that his spittle confers impurity as we explained on verse 2. Alternatively, we would have reasoned that the reason we have to exclude it is only because there was a special letter needed (the letter ו in the word וזאת) to include urine otherwise we would have excluded it.

2טומאתו היא. it is his impurity. In Torat Kohanim the sages explain the logic as follows: If a זב, a male afflicted with this discharge who does not transmit impurity through a discharge of blood, nonetheless transmits impurity when discharging a whitish fluid, a זבה, female equivalent, who transmits impurity when discharging blood (from that orifice), most certainly would also transmit impurity if she discharges a whitish fluid. Therefore the Torah had to write טומאתו היא, it is his impurity, seeing the word טומאתו was quite unnecessary unless it was meant to tell us that a female when in the throes of this disease does not confer impurity by the discharge of a whitish fluid but only by discharging blood. This exclusion is based on the pronoun-ending טומאת־ו as opposed to the pronoun-ending טומאת־ה. We disagree with the author of Korban Aharon who uses the word היא as the basis for this exclusion. When you will examine the exclusion to be derived from the word היא more carefully you will be forced to admit that the word describes the impurity and not the person who has become impure.

3I have already discussed at length the fact that the קל וחומר that Torat Kohanim presents here as a possible reason why the text had to specifically teach us an exclusion is the exact opposite of the קל וחומר the author of Torat Kohanim suggested as a possible reason for the inclusion of the urine in the fluids causing impurity. I have told you that such hypothetical logical approaches are not necessarily final and may be abandoned when new tools of exegsis come to light. Another example had been Torat Kohanim on Leviticus 14,7. We can answer these apparent contradictions by pointing out -as did the Talmud in Niddah 54- that there are elements in the laws about the blood of a menstruating woman which provide us with a reason to consider her as the more stringent case. Details are that her blood confers impurity regardless of whether it is still wet or has already dried whereas the discharge of someone afflicted with זיבה transmits impurity only while it is wet. Also, a menstruating woman causes impurity as soon as she has spotted blood the first time, whereas the blood of a person afflicted with זיבה transmits impurity only after several sightings or sightings on consecutive days respectively. The menstruating woman causes impurity to things she sits on or lies on as soon as she sights her menstruating blood the first time, something that is not the case with a male זב. These factors combined entitle us to assume that discharge of blood should cause impurity, more so than the discharge of a whitish fluid. On the other hand, the fact that a male זב transmits impurity already after several sightings of discharge even on the same day, as opposed to his female counterpart who only causes such impurity, after sighting a discharge on the third of three consecutive days, indicates that his discharge is viewed more severely and that therefore also a bloody discharge of his could confer impurity. For the above cited reasons we can understand why the two apparently contradictory attempts to learn a hypothetical קל וחומר are both reasonable.

4The reason why the Torah wrote the word היא (a second restrictive expression in addition to טומאתו בזובו), may be because the Torah was concerned that unless there was an additonal restrictive expression one might interpret the first such expression as merely reducing the level of impurity the whitish fluid from a זבה transmits i.e. a lower degree of impurity than that transmitted by her blood. Whereas the blood she emits confers ritual impurity on anything she sits or lies on already at the first sighting, the whitish fluid would not have that effect until after several sightings on several days, etc,. I would not conclude, however, that the whitish fluid does not confer impurity at all. Hence the restrictive word היא is needed to teach that whitish fluid issuing from a זבה does not confer impurity at all. Only the male זב confers impurity through emission of a whitish fluid. [I confess I have some problem with this seeing that verse 25 did not mention anything other than the blood of a זבה. Why was there a need to exclude anything other than blood? Ed.]