Rashi: "Rosh Tzurim" and "Gevahos" refer to their beginnings - the Avos and the Imahos ¹ who form the powerful base from which Yisrael descended.

Ramban and Rashbam: 'Because I see them from the mountain-tops and from the top of the hill (that they are alone and other nations are not reckoned together with them - Rashbam). ²

Targum Yonasan: 'I see that this nation is led on the merit of the righteous Avos, who are compared to mountains, and of the Imahos who are compared to hills. ³

Rashi (citing Targum Onkelos): It means that they are a nation who on the merit of their ancestors, will inherit the World to Come - alone.

Rashi #2: It means that, when Yisrael rejoice, no other nation rejoices together with them. ¹

Ramban: It means that they alone are as numerous as the dust of the earth, which nobody can count; neither can was Bil'am able to count the four camps of Yisrael. ²

Rashbam: Refer to 23:9:1:2.

Seforno and Targum Yonasan: It means that they alone will inherit the world to come ³ (because they do not live by the lifestyle of the nations ? Targum Yonasan).

Rashi #1 (citing Targum Onkelos): It means that they will not be destroyed together with the other nations. ¹

Rashi #2: It means that when the other nations have it good, Yisrael share in the benefits without detracting from their reward.

Targum Yonasan: It means 'because they do not follow the customs of the nations of the world.

Sanhedrin, 39b: Even Bil?am, who was a gentile, prophesied that Yisrael would not mix with the nations among whom they were destined to be exiled. ²