“…See, I have given the land before you; Come and possess the land that G-d swore to your forefathers, to Avraham, to Yitzchak, and to Yaacov, to give them and their descendants after them…” – Devarim 1:8

רְאֵה נָתַתִּי לִפְנֵיכֶם אֶת הָאָרֶץ בֹּאוּ וּרְשׁוּ אֶת הָאָרֶץ אֲשֶׁר נִשְׁבַּע ה’ לַאֲבֹתֵיכֶם לְאַבְרָהָם לְיִצְחָק וּלְיַעֲקֹב לָתֵת לָהֶם וּלְזַרְעָם אַחֲרֵיהֶם – דברים א, ח

Moshe recounted to Bnei Yisrael that, when they were yet at Mount Sinai, G-d had expressed His desire to bring them straightaway into the Land of Israel. Moreover, G-d assured them at that time that their conquest of the Land would be swift and uncontested: “See, I have given the land before you; Come and possess the land that G-d promised to your forefathers.” As Rashi explains, this means, “No one will contest the matter, and you will not need to go to war.”

With these words, Rashi identifies two distinct points that were included in G-d’s declaration that the Land was already “given” to Bnei Yisrael, (if not for their sin in the episode of the Spies.)

Firstly, G-d assured Bnei Yisrael that none of the nations would contest their right to the Land on legal grounds. For as Rashi (Beraishis 1:1) explains, this takeover of the Land was legal and legitimate: “All of earth belongs to G-d. He created it [the Land of Israel] and gave it to whomever He saw fit. By His will He give it to them and By His will He took it from them and gave it to us.” Moreover, even nations that descended from Avraham and Yitzchak, who might consider themselves equal heirs to the land that G-d promised to the forefathers, would have no legal claim to the Land. As Bnei Yisrael would (eventually) tell the Edomites, the descendants of Eisav: “You have no right to contest our inheritance of the Land of Israel, since you did not pay the debt [of exile that was decreed upon Avraham’s heirs]” (Rashi, Bamidbar 20:17).

Even with the legal issue settled, however, Bnei Yisrael might have been concerned that the nations living in the Land would not willingly abandon their home without a fight. G-d therefore reassured them, “I have given the Land before you” in this aspect as well. “You will not need to go to war,” for the nations will leave on their own and you will take possession of the Land unopposed.

—Likutei Sichos, vol. 34, pp. 6-7