Question: In light of the spread of the phenomenon of ground water prospecting and well digging in primitive ways relying on what they call “Al-Murzim” or “Al-Mosmi`” i.e. Those who reveal the existence of wells in a particular place. If Al-Murzim or Al-Musmi` finds a good environment, they do not ascribe the knowledge of underground water passages to themselves but refer the matter to Allaah’s knowledge. If they find another environment, they indicate the underground streams of water, its paths, and colors of the earth layers which the digger will encounter and such like Ghayb (the Unseen) matters, which cannot be assigned to proficiency and experience. People are often fascinated by their sayings when they come true. Furthermore, I do not know anyone who does not rely on the statements of Al-Murzim or Al-Musmi` and their like. Indeed, this belief is firm in the hearts of the people and even in the minds of many intellectuals. Although soothsaying and fortunetelling have been rejected in the creedal books, many continue to believe that the prohibition does not apply to Al-Murzim or Al-Musmi` as they call them.
Therefore, we hope that Your Eminence will advise, guide, and clarify the ruling on this question with reference to those who die on this belief. Finally, what are the ways we can use other than Al-Musmi` or Al-Murzim and their likes?
Answer: If testing the earth is intended for discovering what is hidden in its depths by modern equipment and instruments based on experiments conducted on the layers of the earth and previous experience, it is not a part of soothsaying or knowledge of Ghayb, but it is a part of knowing the causes just as doctors diagnose the type of disease through modern medical equipment. Such cases are approved because they are in conformity with the laws of causality that Allaah places in the universe… read more here.