Who says "Ki Vi Chashak"?
Sanhedrin 93a: This was Hashem's Brachah to Shlomo.
Radak: Hashem says so about him. This is why He saves him - He loves him greatly since he desires Hashem.
What is the meaning of "va'Afaltehu Asagevehu"?
Radak: I will be an escape for him, and lift him so no damager can touch him 1 .
Malbim: "Va'Afaltehu" is saving him; Asagevehu is lifting him so he will overpower damagers.
Radak explains as if it says Afaltehu va'Asagevehu; they apply to one who knows His name. Seemingly, va'Afaltehu applies even to one who desires Him (and so explain the other Meforshim), which is a smaller matter! (PF)
What is the significance of knowing His name?
Ibn Ezra: He knows the secret of My name.
Radak: Knowing His four-letter name is the greatest love of Him, and the fullest understanding [of Him] that a person can have while he is [in] a body.
Radak (15, citing Shocher Tov): Now, some pray and are not answered, for they do not know His name. In the future, He will inform them - "Lachen Yeda Ami Shmi" (Yeshayah 52:6).
Metzudas David: Due to this, he zealously fears Me.
Malbim: This is a higher level than desiring Hashem.