They had been married in a secret ceremony in a cellar chapel by a priest of the Resistance, and she had borne her son in her father's house.  
But such a punishment would kill him far too quickly. Instead, the tribe would drive Selim away from their tight-knit community. And on Arrakis, one did not survive without help. Existence in the desert required cooperation, each person doing his part. The Zensunni looked upon stealing -- especially the theft of water -- as the worst crime imaginable.