On that occasion, I commanded [the tribes of Re'uvain and Gad] saying: "G‑d, your G‑d, has given you this land to take possession of it. (When Israel goes to battle) those of you who are in the army [should] pass over [the land] armed, in front of your brothers, the children of Israel, [for you are the mightiest tribe]."

-- Devarim 3:18

Classic Questions:

Why were the tribes of Re'uvain and Gad told to go ahead of the other Jewish people into battle? (v. 18)

Rashi: They would go in front of the Jewish people to battle because they were mighty, and the enemies would fall before them, as the verse states, "He will tear off an arm [of his enemy in one blow, along] with the head" (Devarim 33:20).

Gur Aryeh: Rashi was troubled by the question: Why should the tribes of Re'uvain and Gad be required to lead the battle? It is understandable that they were required to join the battle, and not leave the rest of the Jewish people to fight while they relaxed in their newly acquired inheritance of land—but why should they be required to go first and put themselves in danger more than the others? Rashi answers this question by explaining that the tribes of Re'uvain and Gad went first "because they were mighty."

The Military Leadership of Reu'vain and Gad (v. 18)

Even after the explanation of Gur Aryeh, Rashi's comment on verse 18 presents us with the following problems:

  1. It is commonly accepted that Yehudah (and not Re'uvain or Gad) was the strongest of the tribes. In Parshas Vayechi, Yehudah is described as a "lion," which is the strongest of the animals, and Ya'akov promised Yehudah that "your hand will be on the necks of your enemies" (Bereishis 49:8).

    So how can Rashi write here that the tribes of Re'uvain and Gad were required to lead the battle "because they were mighty," and not the tribe of Yehudah?

  2. In Parshas Matos (Bamidbar 32:17), Rashi writes that the tribes of Re'uvain and Gad were commanded to be "at the head of the invading armies," suggesting they would join together with the other tribes' armies, at their head. However, here Rashi writes that they were required to "go in front of the Jewish people to battle," indicating that the entire armies of Re'uvain and Gad were to go first, followed by the armies of the other tribes. What caused this change of plan?

The Explanation

  1. To explain the verse, "Your hand will be on the necks of your enemies" (Bereishis 49:8), Rashi cites the parallel verse, "And of my enemies, you have given me the back of their necks" (Sam. II 22:41). This means that the enemy will "flee, so that I see the back of their necks" (Metzudas David ibid.). In other words, the unique might of the tribe of Yehudah is that they cause enemies to flee.

    However, the conquest of the Land of Israel was an obligatory war in which the Jewish people were commanded, "You may not allow any soul to live" (Devarim 20:16, a verse already familiar to the reader from Rashi on Vayikra 25:44). So clearly, in this case, where the Jewish people were required to obliterate the enemy, the ability to cause an enemy to flee was not ideal. Therefore Rashi writes that the tribes of Re'uvain and Gad were chosen because "enemies would fall before them, as the verse states, 'He will tear off an arm [of his enemy in one blow, along] with the head,'" i.e., they were effective in annihilating the enemy.

  2. If Moshe had led the Jewish people into the Land of Israel, we can presume that he would have enjoyed a totally miraculous victory, no different from all the other wars which Moshe fought that were won miraculously. Thus, the fact that Moshe did not merit to enter the Land with the Jewish people, and that they were led instead by Yehoshua, gave rise to the need to conquer the land within the natural order.

    When Moshe instructed the tribes of Re'uvain and Gad in Parshas Matos, he was still confident that his prayers to enter the Land would eventually be accepted by G‑d (see Rashi to Bamidbar 27:12), and that he would lead the Jewish people to a miraculous victory. Therefore, he instructed the tribes of Re'uvain and Gad merely to be "at the head of the invading armies." Their presence was primarily symbolic, since their strength to fight a war within the natural order would not in fact be needed under Moshe's miraculous leadership.

    However, when speaking here in our parsha, Moshe had already been told that his prayers to enter the Land had not been accepted (as is related below, 3:26), so he was aware that the conquest would have to take place within the natural order. Therefore, he instructed the tribes of Re'uvain and Gad to "go in front of the Jewish people," i.e., in front of all of the Jewish people, to utilize their effectiveness to the maximum extent.

(Based on Likutei Sichos vol. 9, p. 1ff.)