1)
What is "Tuv Ta'am [va'Da'as]"?
1.
Radak: It is the best reasons for Torah and Mitzvos.
2.
Malbim: [Teach to me] all details of the Mitzvos and their laws; this is Da'as. Also, I should understand Tuv Ta'am (their reasons).
2)
Why does it say "Ki v'Mitzvosecha He'emanti"?
1.
Radak: I believe that You commanded them, and they are righteous. Therefore teach to me their good reasons!
2.
Malbim: Do not say that I request Tuv Ta'am because I do not believe in Mitzvos for which I do not understand the reason - I believe in them even without understanding!
