Why does it say "v'Nasan Artzam l'Nachalah"?
Radak: This was a Chesed. Not only did He strike them - He also gave their land for an inheritance, and other nations did not come and gather to dispossess Yisrael from there. Hashem gave to Avraham only west of the Yarden, the land of the seven Kena'ani nations 1 . This Mizmor does not mention the kings of Kena'an 2 , for giving their land was not Chesed, rather, Emes (fulfilling His promise to Avraham).
Radak: In the future, three more will be added - Kini, Kenizi and Kadmoni. And even before that time, David ruled over them; Bereishis Rabah 44:3 says that they are Amon and Mo'av. Bereishis 15:19-21 lists all 10; "ha'Refa'im" is Chivi.
Unlike Rashi, who says (17) that "Melachim Gedolim" refers to the 31 kings. (PF)
