From "Manual of Muad'Dib" by the Princess Irulan

Book Two

MUAD'DIB
When my father, the Padishah Emperor, heard of Duke Leto's death and the manner of it, he went into such a rage as we had never before seen. He blamed my mother and the compact forced on him to place a Bene Gesserit on the throne. He blamed the Guild and the evil old Baron. He blamed everyone in sight, not excepting even me, for he said I was a witch like all the others. And when I sought to comfort him, saying it was done according to an older law of self-preservation to which even the most ancient rulers gave allegiance, he sneered at me and asked if I thought him a weakling. I saw then that he had been aroused to this passion not by concern over the dead Duke but by what that death implied for all royalty. As I look back on it, I think there may have been some prescience in my father, too, for it is certain that his line and Muad'Dib's shared common ancestry.

—"In My Father's House," by the Princess Irulan

"Now Harkonnen shall kill Harkonnen," Paul whispered.

He had awakened shortly before nightfall, sitting up in the sealed and darkened stilltent. As he spoke, he heard the vague stirrings of his mother where she slept against the tent's opposite wall.
Paul glanced at the proximity detector on the floor, studying the dials illuminated in the blackness by phosphor tubes.
"It should be night soon," his mother said. "Why don't you lift the tent shades?"
Paul realized then that her breathing had been different for some time, that she had lain silent in the darkness until certain he was awake.
"Lifting the shades wouldn't help," he said. "There's been a storm. The tent's covered by sand. I'll dig us out soon."
"No sign of Duncan yet?"
"None."
Paul rubbed absently at the ducal signet on his thumb, and a sudden rage against the very substance of this planet which had helped kill his father set him trembling.
"I heard the storm begin," Jessica said.
The undemanding emptiness of her words helped restore some of his calm. His mind focused on the storm as he had seen it begin through the transparent end of their stilltent—cold dribbles of sand crossing the basin, then runnels and tails furrowing the sky. He had looked up to a rock spire, seen it change shape under the blast, becoming a low, Cheddar-colored wedge. Sand funneled into their basin had shadowed the sky with dull curry, then blotted out all light as the tent was covered.
Tent bows had creaked once as they accepted the pressure, then—silence broken only by the dim bellows wheezing of their sand snorkel pumping air from the surface.
"Try the receiver again," Jessica said.
"No use," he said.
He found his stillsuit's watertube in its clip at his neck, drew a warm swallow into his mouth, and he thought that here he truly began an Arrakeen existence—living on reclaimed moisture from his own breath and body. It was flat and tasteless water, but it soothed his throat.
Jessica heard Paul drinking, felt the slickness of her own stillsuit clinging to her body, but she refused to accept her thirst. To accept it would require awakening fully into the terrible necessities of Arrakis where they must guard even fractional traces of moisture, hoarding the few drops in the tent's catchpockets, begrudging a breath wasted on the open air.
So much easier to drift back down into sleep.
But there had been a dream in this day's sleep, and she shivered at memory of it. She had held dreaming hands beneath sandflow where a name had been written: Duke Leto Atreides . The name had blurred with the sand and she had moved to restore it, but the first letter filled before the last was begun.
The sand would not stop.
Her dream became wailing: louder and louder. That ridiculous wailing—part of her mind had realized the sound was her own voice as a tiny child, little more than a baby. A woman not quite visible to memory was going away.
My unknown mother , Jessica thought. The Bene Gesserit who bore me and gave me to the Sisters because that's what she was commanded to do. Was she glad to rid herself of a Harkonnen child?
"The place to hit them is in the spice," Paul said.