What is the meaning of "[Pi Tzadik] Yanuv [Chachmah]"?
Rashi: He will speak. This is like "Niv Sefasayim" (Yeshayah 57:19).
R. Yonah: It is an expression of fruits, like "u'Malu Pnei Sevel Tenuvah" (Yeshayah 27:6), "mi'Tenuvos Sadai" (Eichah 4:9). A Tzadik's mouth will produce Chachmah. He accustomed his lips with Chachmah, until Chachmah became to them like fruits to a tree. They do not speak without Chachmah.
Malbim: Regarding "Pi Tzadik Mekor Chayim" (11), I explained that a Tzadik did not gather the laws of Chachmah from Kabalah. Rather, he accustomed to go in them via his virtue. Via this, he can teach about how to conduct with Chachmah in every detail, even though he did not have Torah of the Kelalim like a Chacham does. His source of Chachmah is his mouth; it makes the fruits. When people ask him how to conduct in a particular case, his Chachmah will sprout with Tevunah - a proper answer according to Chachmah. He has an advantage over a Chacham (refer to 10:31:2:2).
What is "Leshon Tahpuchos [Tikares]"?
R. Yonah: It speaks the opposite of Emes. It says good about bad, and vice-versa. It strengthens Sheker and supports Shav. Switching Emes is the opposite of Chachmah. The verse curses this Midah even before mentioning that it is the Rasha's Midah (verse 32), for it is very despised.
Malbim: The tongue denotes the ways of Binah. If he brings proofs of Tevunah in the way of investigation that are opposite to Chachmah, the Chacham cannot oppose him, for the Chacham is not Navon (to understand a matter amidst another matter). His Chachmah is only received; he does not know to clarify it with proofs against an investigator who contradicts its cornerstones. However, the Tzadik can bring against him proof of experience. He already tested every particular matter until he attained clear knowledge like sensory proofs. Therefore, a tongue that brings proofs of Tevunah against Chachmah, it cannot stand in front of a Tzadik.
