Aḥmad also said, in the narration of Abū al-Ṣaqr, concerning dead land in the Abode of Islam whose owners were unknown and upon which the ruler levied no kharāj: “If a Muslim revives land outside the Sawād, the ruler may levy only its ʿushr from him; he has no right to anything else.”

As for the protected area of the dead land he revives for habitation or cultivation, it is determined by what that land cannot do without: its access road, its open space, and its watercourse for drawing water and drainage. He said, in the narration of Yūsuf ibn Mūsā: “Dead land that no one owns is land in the wilderness or desert; but if it lies between villages, it is not [considered dead land].”

In the narration of ʿAlī ibn Saʿīd, he was asked about meadows near Medina that served as pasture for livestock, where the dead were buried, and for which no owner was known. He replied: “I do not think anyone should interfere with them when they are in this condition and close to the village.” He later said: “If taking possession of them causes no harm to anyone, then they belong to whoever revives them.”

If a great river—such as the Tigris, Euphrates, or Nile—recedes from a tract of land, no one may revive it. He expressly stated this in the narration of Ibn Ibrāhīm, concerning the Tigris: when an island containing paths formed in its midst and some people took possession of it, he said: “How can they take possession of it when it is something no one owns?” In the narration of Yūsuf ibn Mūsā, he said: “If the water recedes from an island as far as a man’s open space, may he build on it?” He replied: “No, for that would harm someone else, since the water will return.”

The Companions established Basra as a city during the time of ʿUmar and laid it out in allotments for the tribes living there; they set the width of