White Hair

The beginning of this week's פרשה contains many instances of the מפיק ה, indicating the female, third-person possessive. The proper pronunciation of these is more critical than usual as we find the word טהרה both with and without. The absence of an expected מפיק ה would certainly change the meaning. There is another such instance later on. In the discussions of the various laws of צרעת, there are a number of references to hair. In 13:20, when the כהן observes the white hair, the word ושערהּ has a מפיק ה as expected, indicating that its hair turned white. However, earlier on, (13:4) in reference to hair that has not turned white, we find the very same word without a מפיק ה. Most חומשים go out of their way to call attention to this apparent anomaly.

I had originally thought that this was simply another one of the many grammatical anomalies found in the תורה, such as the missing דגש in the שׂ of the last word of פסוק י in this very פרק. However, I found a very logical explanation for this in משך חכמה. In the later reference to the hair, rewinding to the beginning of the paragraph reveals that the subject is בשר, flesh. That is why ושערהּ is punctuated in the possessive form, because the hair emanates from the flesh. However, the subject of the earlier pasuk is עור, the skin. Although the hair appears to be coming from the skin, in truth, it comes from the flesh underneath it so the non-possessive form without the מפיק ה is used.

A reader offered the following alternative approach which seems more plausible, partially due to MDJ's question in the comments:

Note that “Hair” in English has two separate connotations – either referring to individual strand of hair, or to a collection of strands. I suggest se’ara (the fem. Form) has the former meaning, and se’ar (masc.) the latter.
When we describe a situation where white hair has appeared, it may be a minimal amount or (more typically) an entire section, so “hair” is used in the collective sense.When we describe the opposite situation, we say not one strand of hair has turned white.
Thus:In 13:3 which speaks of some hair turning white, the masculine form se’ar is used.In 13:4, the condition described is that no hair (not even a minimal number of individual strands) has turned white – so the feminine form denoting a strand is used.And in 13:20, which (like 13:3) speaks of some of “its” hair having turned white, we are back to the masculine form, but with a feminine possessive suffix added.