By Rabbi Yair Hoffman for 5tjt.com

Rav Yisrael Lifschitz (1782-1860), author of the Tiferes Yisroel commentary on the Mishna, posed the question as to why there is no longer Tumas Negayim in modern times.  Maran Rav Chaim zatzal identified another source that resolves the question – The Midrash Lekach Tov (Parshas Tazria explains that once the Bais HaMikdash was destroyed – there was no longer tumas Negayim.

As far as Negayim are concerned, the Tosefta 1:1 explains that the main idea is that the Cohen be proficient in knowing them, otherwise, he should not be involved in declaring Begayim.  In regard to matters other than Negayim, however, such as specific halachos is not to be considered as being “non-proficient.”

In regard to how Kohanim will know what to do in the Avodah when the Bais HaMikdash will be rebuilt (quickly in our days) it will not be a problem of non-proficiency.  What will happen b’ezras Hashem isall the sages of Israel will gather, and they will be machriah – as to which opinion will be followed. Even though we say that a later Bais Din may not negate the ruling of an earlier Bais Din unless it is greaterin both wisdom and in number, that is not what is happening.

https://orchotyosher.org/parshas-metzorah-non-proficiency/

for more Torah from Maran Rav Chaim zatzal go to orchotyosher.org