Numbers 23:9

For I view it from the mountain peaks (lit. head of the mountains). I gaze at their origins, the beginnings of their roots, and I perceive that they are well founded and powerful, like the mountains and the hills, because of the patriarchs and the matriarchs.

Behold! A people which shall dwell alone. This was acquired for them by their forefathers — to dwell alone, as rendered by Targum [Onkelos].

And will not be reckoned among the nations. As Targum [Onkelos] explains, they will not be annihilated with the other nations, as it is said, “for I shall annihilate all the nations, etc.” They will not be reckoned with the rest. Another interpretation: When they rejoice, no nation rejoices with them, as it is said, “God shall give them repose alone.” But when the nations prosper, they partake with each of them, without debiting the balance of their account. This is [the meaning of] “and will not be reckoned among the nations.”

For, said Bileam the wicked, I look on this people who are led on for the sake of their righteous fathers, who are like the mountains, and of their mothers, who are like the hills: behold, this people alone are to possess the world, because they are not led by the laws of the nations.

FOR FROM THE TOP OF THE ROCKS I SEE HIM. The meaning of this is that since Balak had brought him up to Bamoth-baal [which was a high place] to see Israel, Balaam said: “From the top of the rocks and from the hills I look and I see him, for he [is a people that] shall dwell alone, and there is no other nation with him that can be counted together with him, in the way that many [different] peoples and various nations gather together to become one camp — for these [people of Israel] all have one law and one ordinance,, 15:16. and are one nation, dwelling alone by the name of Jacob and Israel.” Therefore he [Balaam] mentioned, Come, curse me Jacob, and come defy Israel, referring to them [both] by their name of honor [Israel] and by the name of their ancestor [Jacob], meaning to say that they are a people alone, and have names befitting them from their ancestors. For Balak did not tell him [Balaam] the name “Israel,” but merely said, Behold, there is a people come out from Egypt, as if he was a stranger to them and did not know them, and he was not grateful for the favor that their father had done. And the meaning of Balaam’s words is that “just as I see him now dwelling alone, so will he forever dwell in safety, the fountain of Jacob alone, and he will always be at the head, for no nation will [ever] prevail over him [and cause him to perish], and he will never become assimilated to them [i.e., other nations].

כי מראש צורים אראנו, Bileam now explains why G’d has not angered Israel and does not want to curse them. Now that Bileam has a chance to view their camp from the vantage point of a high rock and from a hilltop, he had begun to appreciate the solitary manner in which this people remains pure, not intermingling with other nations. Not only that, but they have a countless number of small children. The Jewish people are not counted until they have attained age twenty. It follows that they are far more numerous than the census figures would indicate.

הן עם לבדד ישכון, in the final analysis, they are the only people who will eventually populate the earth. This concept is repeated by Moses in Deuteronomy 32,12 ה' בדד ינחנו, “the Lord will guide only them alone.” It will be impossible to destroy them.