כלי יקר — והצרוע אשר בו הנגע

Q — Why does the Torah say 'והצרוע *אשר בו הנגע*' — isn't 'הצרוע' enough, since a metzora by definition has the affliction?

A — Kli Yakar distinguishes צרעת (the strike — the symptom on the body) from נגע (the underlying flaw). The Torah is encoding Chazal's principle (Kiddushin 70a): 'כל הפוסל במומו פוסל' — anyone who casts aspersions on others is suspected of having the very fault he names. The metzora was struck because he spoke לשון הרע to expose the flaws of others. The verse therefore says: the one struck on the surface ('הצרוע') is the one who actually *has* the underlying flaw ('אשר בו הנגע') — the very disgrace he tried to pin on his fellow was his own all along.