The Zohar, Chapter “VeYechi (And Jacob Lived),” Item 551: “Reckless as water, you shall not have preeminence” because when the sons of Reuben wage war in the world and defeat many nations, the sons of Reuben will not remain in kingship because they will make war in the holy land.
As the authors of The Book of Zohar describe the systems of the worlds and phenomena to us (and to the extent that they do it), they perform multiple corrections in this system of governance. It seems to us that they simply tell us about the events that took place in the past. However, when the Kabbalists go through the spiritual states that they tell us about, they reveal them within themselves and by doing so, correct them. In doing so, they prepare for us the space that has already been corrected so that we could ascend to it.
From the 2nd part of the Daily Kabbalah Lesson 10/4/10, The Zohar