Midrash su Deuteronomio 33:6

(Fol. 7b) Our Rabbis were taught: The court reads before her (the Sata) parables and incidents mentioned in the first Hogiograph, like the one (Job 15, 18) Which wise men have ever told, and have not concealed, as they obtained it from their father. This refers to Juda, who confessed [his crime] and did not feel ashamed. What was the result? He succeeded to inherit the future world. Reuben confessed and did not feel ashamed. What was the result of his confession? He succeeded to inherit the future world. And what was their reward? Why, we have just said what their reward was. The question must therefore be explained thus: What was their reward in this world? (Ib., ib. 19) Unto whom alone the land was given, and no stranger passed among them. It is readily understood in regard to Juda's confession, for we find that he did confess, as stated in the following passage (Gen. 39, 26) And Juda acknowledged them, etc. "But as to Reuben, whence do we know that he did confess?" said R. Samuel b. Nachman (as fully explained Babba Kamma 92). ...

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When thou takest the sum of the children of Israel (Exod. 30:12). R. Yosé the son of Hanina said: This verse indicated to him that in the future he would bring the first of the tribes to the Shekhinah. But which one was the first tribe? It is Reuben, as it is said: Let Reuben live and not die (Deut. 33:6). This is what is meant by Thou liftest up the head (rosh) of the children of Israel; i.e. he lifted up the first (rishon) of the tribes.