Did a quick google and here’s the water of life passage that references his earlier prescient visions that he discussed with his mother.
“Paul swallowed. He felt that he played a part already played over countless times in his mind…yet…there were differences. He could see himself perched on a dizzying summit, having experienced much and possessed of a profound store of knowledge, but all around him was abyss. And again he remembered the vision of fanatic legions following the green and black banner of the Atreides, pillaging and burning across the universe in the name of their prophet Muad’Dib. That must not happen, he told himself.”
Even at the end of the book he is working to stop it.
“In a rush of loneliness, Paul glanced around the room, noting how proper and on-review his guards had become in his presence. He sensed the subtle, prideful competition among them—each hoping for notice from Muad’Dib. Muad’Dib from whom all blessings flow, he thought, and it was the bitterest thought of his life. They sense that I must take the throne, he thought. But they cannot know I do it to prevent the jihad.”