Who are "Chasidecha"?
Rashi: They are Nasan ha'Navi and Gad ha'Chozeh.
Radak: It is Shmuel ha'Navi.
Malbim: It is Nasan ha'Navi.
What is the meaning of "va'Tomer Shivisi Ezer Al Gibor"?
Radak: You told [Shmuel] that You put help for Yisrael on a Gibor, i.e. David - "v'Lech Eshlachacha El Yishai Beis ha'Lachmi Ki Ra'isi b'Vanav Li Melech" (Shmuel I, 16:1).
Malbim: This corresponds to Emunah - bestowing according to the recipient's preparation. "Shivisi" is putting something on something according to its value and what is proper for it. David is a Gibor, and proper to receive an influence of Gevurah.
What is the meaning of "Harimosi Vachur me'Am"?
Radak: "Va'Yimshach Oso b'Kerev Echav" (Shmuel I, 16:13). He is called Bachur, for he was chosen for kingship.
Malbim: This corresponds to Chesed - I lifted him from the nation because I chose him, not due to any preparation.
