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

I must accept that water , Paul thought. Slowly, he arose, made his way to Chani's side. Stilgar stepped back to make room for him, took the baliset gently from his hand.
"Kneel," Chani said.
Paul knelt.
She guided his hands to the waterbag, held them against the resilient surface. "With this water the tribe entrusts thee," she said. "Jamis is gone from it. Take it in peace." She stood, pulling Paul up with her.
Stilgar returned the baliset, extended a small pile of metal rings in one palm. Paul looked at them, seeing the different sizes, the way the light of the glowglobe reflected off them.
Chani took the largest ring, held it on a finger. "Thirty liters," she said. One by one, she took the others, showing each to Paul, counting them. "Two liters; one liter; seven watercounters of one drachm each; one watercounter of three-thirty-seconds drachms. In all—thirty-three liters and seven and three-thirty-seconds drachms."
She held them up on her finger for Paul to see.
"Do you accept them?" Stilgar asked.
Paul swallowed, nodded. "Yes."
"Later," Chani said, "I will show you how to tie them in a kerchief so they won't rattle and give you away when you need silence." She extended her hand.
"Will you . . . hold them for me?" Paul asked.
Chani turned a startled glance on Stilgar.
He smiled, said, "Paul-Muad'Dib who is Usul does not yet know our ways, Chani. Hold his watercounters without commitment until it's time to show him the manner of carrying them."
She nodded, whipped a ribbon of cloth from beneath her robe, linked the rings onto it with an intricate over and under weaving, hesitated, then stuffed them into the sash beneath her robe.
I missed something there , Paul thought. He sensed the feeling of humor around him, something bantering in it, and his mind linked up a prescient memory: watercounters offered to a woman—courtship ritual .
"Watermasters," Stilgar said.
The troop arose in a hissing of robes. Two men stepped out, lifted the waterbag. Stilgar took down the glowglobe, led the way with it into the depths of the cave.
Paul was pressed in behind Chani, noted the buttery glow of light over rock walls, the way the shadows danced, and he felt the troop's lift of spirits contained in a hushed air of expectancy.
Jessica, pulled into the end of the troop by eager hands, hemmed around by jostling bodies, suppressed a moment of panic. She had recognized fragments of the ritual, identified the shards of Chakobsa and Bhotani-jib in the words, and she knew the wild violence that could explode out of these seemingly simple moments.
Jan-jan-jan , she thought. Go-go-go .
It was like a child's game that had lost all inhibition in adult hands.
Stilgar stopped at a yellow rock wall. He pressed an outcropping and the wall swung silently away from him, opening along an irregular crack. He led the way through past a dark honeycomb lattice that directed a cool wash of air across Paul when he passed it.
Paul turned a questioning stare on Chani, tugged her arm. "That air felt damp," he said.
"Sh-h-h-h," she whispered.
But a man behind them said: "Plenty of moisture in the trap tonight. Jamis' way of telling us he's satisfied."
Jessica passed through the secret door, heard it close behind. She saw how the Fremen slowed while passing the honeycomb lattice, felt the dampness of the air as she came opposite it.
Windtrap! she thought. They've a concealed windtrap somewhere on the surface to funnel air down here into cooler regions and precipitate the moisture from it .
They passed through another rock door with latticework above it, and the door closed behind them. The draft of air at their backs carried a sensation of moisture clearly perceptible to both Jessica and Paul.
At the head of the troop, the glowglobe in Stilgar's hands dropped below the level of the heads in front of Paul. Presently he felt steps beneath his feet, curving down to the left. Light reflected back up across hooded heads and a winding movement of people spiraling down the steps.
Jessica sensed mounting tension in the people around her, a pressure of silence that rasped her nerves with its urgency.
The steps ended and the troop passed through another low door. The light of the glowglobe was swallowed in a great open space with a high curved ceiling.
Paul felt Chani's hand on his arm, heard a faint dripping sound in the chill air, felt an utter stillness come over the Fremen in the cathedral presence of water.