When does "Ten l'Chacham v'Yechkam Od" apply?
Shabbos 113b: Na'ami told Rus to bathe, anoint, put on her Shabbos clothing and go to the granary. Rus went to the granary first [lest people see her adorned and suspect that she is a harlot].
Rashi: It applies to a proper Talmid.
Rashi citing a Midrash: Hashem told Noach to take [seven and seven] from every Tahor species. After he left the ark, he reasoned, why did Hashem command me to take extra Tehorim? He wanted me to offer Korbanos from them!
Malbim: Chachmah is very vast, and there is no limit to its Mitzvos. Also a Chacham will always receive laws of Chachmah and add to his Chachmah.
What should one inform a Tzadik?
Rashi: Chachmah.
Malbim: Tzadik is not the same a Chacham. A Chacham received all the laws of Chachmah. A Tzadik conducts justly, even though he does not know the laws of Chachmah like a Chacham. He is used to them from habit, via great Shimush - Shimush of Torah is greater than learning it (Brachos 7b). He must be informed the laws of Chachmah.
How will he add "Lekach"?
Rashi: He will add from his Da'as to what he heard.
Malbim: He will add to what he already conducted via habit and Shimush.
