7. Muhammad ibn Yahya has narrated from Muhammad ibn Al-Husayn from Muhammad ibn ‘Abd Allah ibn Hilal from ‘Uqbah ibn Khalid who has narrated the following:

“Abu ‘Abd Allah , has said that if a man digs a well (a canal) in a hill which reduces the water of an existing well or canal, they must be examined closely. Such tests must be conducted every night to find out which one reduces the water of the other. If it is found out that the second one reduces the water of the existing, one then it must be closed.’”