What does "Vehikriv oso ... " mean?
Rashi: It means that the Kohen brings the Asham into the Azarah in order to wave it.
Why does the Metzora bring an Asham?
Seforno: Whereas a Chatas atones for a Chiyuv Kares, an Asham atones for a breach of Kedushah, which in this case incorporates Lashon ha'Ra
both of which push away the Shechinah.
Which is generally spoken in secret (which in effect, is an attempt to hide one's actions from Hashem [Seforno]).
The Gemara in Sotah, 5a (based on Tehilim, 101:2) says that Hakadosh-Baruch-Hu says about a haughty person 'he has stolen My robes; I and he cannot live together in the same world!' See also Divrei ha'Yamim 2, 26:16-19.