When Moses blessed the tribe of Gad, he said, “He provided the first part for himself, for there the ruler’s portion was reserved; and he came with the leaders of the people; He executed the justice of the LORD, and His ordinances with Israel” (Deuteronomy 33:21). Who is the “he” in this blessing? Tradition applies these descriptions to Moses himself.
The tribe of Gad settled in Transjordan. The sages understood the obscure words “for there the ruler’s portion was reserved” to refer to the grave of Moses (Deuteronomy 33:21). The Talmud says that the “ruler’s portion” in Gad is the burial plot of Moses.
Though Mount Nebo was located in the territory of Reuben, the sages imagined that the angels carried Moses into the adjacent territory of Gad for burial. Moreover, the midrash interprets Deuteronomy 33:21, “He came at the head of the people,” to mean that Moses will lead his generation across the Jordan and into the land of Israel at the time of the resurrection of the dead. This is why the LORD did not allow Moses to cross the Jordan. He needed Moses to stay with his generation so that his merit and favor could save the generation that he buried in the wilderness:
Lest people suppose that the generation that fell in the wilderness has no share in the World to Come, you must be buried beside them. Then in the time to come, you shall enter with them, as it says, “For there the ruler’s portion was reserved; and he came at the head of the people.” (Numbers Rabbah 19:13)
The generation of Moses would merit to partake in the resurrection only due to Moses being buried on the East Bank of the Jordan, just as they were. Moses identified himself as one with the people, and the LORD referred to Israel as the people of Moses, as it says in Exodus 32:7, “Go down at once, for your people.” Chayim ben Attar notes that the operative word here is “your people,” i.e. that in order to save his people at the time of the resurrection, Moses had to die here and now.
Compare this legend about Moses with the Messiah Yeshua who also died in order to save Israel in the future resurrection. He took the first part for himself, i.e., He was the first raised from the dead. In the future, He will come at the head of the resurrection, leading His people into the land of Israel like a king at the head of his army.