כי מנגד תראה את הארץ "For, from a distance, shall you see the Land" (Debarim 32:52). Previously G-d referred to the land as the Land of Canaan, but in this verse He simply refers to it as "the Land". The reason is because what G-d meant by the "Land", was not only the Land of Israel, which Moshe Rabbenu, 'a"h, would not be entering before his death, but also the "Land" of the world to come, which he would be entering imminently.
The term את הארץ "the Land", included both Yerushalayim (Jerusalem) on earth and the Yerushalayim in Heaven. Furthermore, the word תראה "you shall see", implies that it is not just the physical eye, but also his mind's eye that would see and understand the Land.
So when the Torah writes מנגד "from a distance/opposite", this could refer to seeing a land which was apart from the land of Canaan. Therefore, it was not enough to rely on the earlier verse stating that he would not enter there, but it was also necessary to specify the land "which I shall give to the Children of Israel", to tell Moses that this was the only land that he would not enter. The world to come would be waiting for him.
(See Rabbenu Bahyei on the Torah Ebarim 35:52)
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