Why does it say "Ki Hizharto Tzadik"?
Radak: The pronoun precedes the noun. We find like this, e.g. "va'Yshano Es Taimo" (Shmuel I, 21:14).
Malbim: Do not say that he will not heed you, and via your warning, he will reverse to become a Rasha. Surely he will heed you!
Who is "Tzadik l'Vilti Chato"?
Radak: It is one who was already a Tzadik, and he does not retract from this.
Malbim: He does not do even a small sin of Shogeg, for it is considered Mezid for him.
Why does it say "Chayo"?
Radak: This is like Chayah; there is a Vov in place of a Hei, the last letter of the root.
Why does it say "v'Atah Es Nafshecha Hitzalta"?
Malbim: Via warning him, you cause him to be careful, and live - and also, you save yourself.
