That also was accounted a land of giants - That was accounted the land or territory of the Rephaim.
Zamzummims - Supposed to be the same as the Zuzim, Genesis 14:5. Of these ancient people we know very little; they were probably inconsiderable tribes or clans, "pursuing and pursued, each other's prey," till at length a stronger totally destroyed or subdued them, and their name became either extinct or absorbed in that of their conquerors. From the 10th to the 12th, and from the 20th to the 23d verse inclusive ( Deuteronomy 2:10-12, Deuteronomy 2:20-23;), we have certain historical remarks introduced which do not seem to have been made by Moses, but rather by Joshua or Ezra. By the introduction of these verses the thread of the narrative suffers considerable interruption. Dr. Kennicott considers both these passages to be interpolations. That they could not have made a part of the speech of Moses originally, needs little proof.
These verses, like Deuteronomy 2:10-12, are in all likelihood an addition made by a later reviser.
Deuteronomy 2:20
Zamzummims - A giant race usually identified with the Zuzims of Genesis 14:5.
Deuteronomy 2:23
The Avims which dwelt in Hazerim, even unto Azzah - Read (Gaza, of which Azzah is the Hebrew form. “Hazerim” is not strictly a proper name, but means “villages,” or “enclosures,” probably such as are still common in the East. The Avims are no doubt identical with the Avites of Joshua 13:3, and were doubtless a scattered remnant of a people conquered by the Caphtorim (Genesis 10:14 note) and living in their “enclosures” in the neighborhood of Gerar. The word, which means “ruins,” seems itself expressive of their fallen state.