The Ruling on Prostrating on the Soil of Karbala

The fourth and final question in the letter from our brother Sabri al-Jaburi from the Iraqi Republic says: Is it permissible to pray on the soil, and what is its benefit during prayer? Please clarify the ruling on this act for us?
Answer: It seems the questioner is referring to the soil that the Shi'ah are accustomed to using, which is a stone they claim is from Karbala so that they prostrate on it. This is a religious innovation (bid'ah) with no basis, and it is not permissible to pray on it, but the prayer is not invalidated. However, it is a religious innovation (bid'ah) that is not permissible to do, and this is something the Shi'ah have introduced. May Allah guide them and protect us and them from Satan.
The point is that this is a religious innovation (bid'ah), and a person should not move the soil from one place to another to pray on it. Rather, he should pray on whatever is available. If he is on gravel, he prays on the gravel; if he is in sand, he prays in the sand; if he is in a mosque with carpets, he prays on the carpet. He has no right to carry a stone, clay, a piece of wood, or anything else to prostrate on. This is among the innovations that involve adding to the religion. Yes.