“We will treat your comrade with the same reverence we treat our own,” the Fremen said. “This is the bond of water. We know the rites. A man’s flesh is his own; the water belongs to the tribe.”
In the beginning of Book II, a member of the Fremen speaks these words to Thufir Hawat, a Mentat who served three generations of Atreides until he reluctantly joined the Harkonnens. Hawat allows the Fremen to take the dead body of one of his soldiers to be rendered down for water. For the Fremen, water is more important than blood. Alliances are secured with the “bond of water” rather than with blood oaths. Fremen remove the water from a body once it dies. They keep the water for the tribe, or they store it in wells, where it will eventually be used to alter the climate of Arrakis. Hawat, by allowing his own men’s corpses to be tapped for precious water, creates a strong bond between his men and the Fremen.