Musannaf Ibn Abi Shaybah

Hazrat Umar al-Dhabi, may Allah have mercy on him, says that while the people of Sabur were softening the land—or he said: they were plowing the land—they found a treasure. And over them, Hazrat Muhammad bin Jabir al-Rasbi was the governor. So he wrote a letter to Hazrat 'Adi, may Allah have mercy on him, regarding this matter. And Hazrat 'Adi, may Allah have mercy on him, wrote a letter to Hazrat Umar bin Abdul Aziz, may Allah have mercy on him, inquiring about this matter. Hazrat Umar bin Abdul Aziz, may Allah have mercy on him, replied: Take one-fifth (khums) from them.