What is the significance of the statement "Ki li'Venei Lot Nesatihah Yerushah"?
Rashi: Refer to 2:5:2:1*.
Rashbam: If the B'nei Lot received their inheritance because their father was a relative of Avraham, how much more so you, who are his children, will receive yours. 1
What is the significance of the statement "Eretz Refa'im Techashev Af Hi"?
Rashi and Rashbam: The Zamzumim, who originally inhabited the land of Amon, were called 'Refa'im', just like the Eimim (whose land Mo'av took over), only this is not Eretz Refa'im 1 that Hashem gave to Avraham (Bereishis 15:20) who originally inhabited the land of Amon, were called 'Refa'im', just like the Eimim (whose land Mo'av took over). In fact, they are synonymous with the Refa'im whose land Hashem gave to Avraham, 2 only the Mo'avim and the Amonim changed their names on account of their stupendous strength. 3
Why did the Amonim call the Refa'im 'Zamzumim'?
Ramban, Targum Onkelos and Targum Yonasan: The word means 'conspirators' 1 - because whatever they planned to do they accomplished successfully.
Hadar Zekenim: They were Chachamim and war strategists. Bereishis Rabah says that they were crafty in war.