As you may be aware, Sajdah is not only a part of Salat, but in fact is a superb worship in itself. Furthermore, one is required to prostrate (perform Sajdah) while reading certain verses of the Holy Quran. According to teachings of Prophet Muhammad (PBUH&HP), prostration is considered the closest position of a servant to Allah (SWT). (1) Therefore, due to the significance of Sajdah, it is very important that Muslims perform it correctly. One of the requirements for the validity of Sajdah is the place where we can prostrate on. Since we can not find out the correct way of performing Sajdah using our wisdom, we have to investigate our religion to see how Allah (SWT) has taught us to perform Sajdah correctly.
Sajdah and Shia
According to the teachings of Ahl al-Bayt (PBUT), under normal circumstances we must perform Sajdah on earth, on its components, or on what grows from the earth (except the things that are edible or used in manufacturing cloth). (2) Thus, except for the edible and clothing plant products, we can prostrate (perform Sajdah) on anything that is a component of earth, i.e. soil, stone, sand, or plants. However, amongst the wide variety of things permissible to perform Sajdah on, earth is the most recommended and Ahl al-Bayt (PBUT) have encouraged us to perform Sajdah on earth when possible. The concern that remains is that in this day and age, it is not always possible to find clean earth, so as a solution Shiites have made earth in the form of Turbah, so that they are confident about its cleanliness and can easily carry it wherever they want.
Understanding Prophet Muhammad's (PBUH&HP) tradition
Shiites believe that the Infallible Imams (PBUT) are the most superior, reliable and authentic sources of Prophet Muhammad's (PBUH&HP) narrations and traditions. As they have stated in various narrations, they have learned everything they teach us from Prophet Muhammad (PBUH&HP) himself. This belief is not restricted to Shiites, since a lot of great Sunni scholars accept the Imams (PBUT) as authentic narrators and narrate great number of Hadiths from them. Therefore, the words of Ahl al-Bayt (PBUT) about prostration are sufficient for us to be assured that Prophet Muhammad (PBUH&HP) prostrated the same way.
The Infallible Imams (PBUT), however are not the only ones who have explained the way one must prostrate; as a matter of fact several narrators amongst the companions and the followers of the Prophet (PBUT&HP) have also narrated Hadiths, which indicate Prophet Muhammad's (PBUH&HP) traditions in this regard. The significance of these narrations is that all Muslim scholars, Shia and Sunni (in Sihah Sittah), have agreed upon the authenticity of them. In order to create a common ground in that our Sunni brothers can also rely on, we will provide verses from the Holy Quran and narrations from the Sunni authentic sources.
Prophet Muhammad's (PBUH&HP) place of Sajdah
According to the most authentic juristic books of both Shiites and Sunnis, Prophet Muhammad (PBUH&HP) has said:" The earth has been considered as a place for prostration and an object that cleanses."(3) In this Hadith, Prophet Muhammad (PBUH&HP) has explicitly introduced earth as a place to prostrate on. Thus, it is permissible to prostrate on earth and its components like soil, stone, and etc.
Prophet Muhammad's (PBUH&HP) has not only specified the place of prostration, but has also shown the correct way of prostrating through his own practice. Wa'il - the companion of Prophet Muhammad (PBUH&HP) - has narrated:" I saw the Prophet putting his forehead and his nose on the earth while prostrating." (4)
Abu Hurayra and Abi Sa'eed Khidri have also confirmed this fact through the following narration: "Although the earth had become wet due to the rain, Messenger of Allah prostrated on the earth and we saw its trace on his forehead." (5)
Aisha has narrated that the Prophet never covered his forehead with anything during prostration (6), and he would never allow his turban to cover his forehead and get in the way of his place of prostration. (7)
Based on the mentioned narrations, it is clearly indicated that even in unusual situations like the time of rain, Prophet Muhammad (PBUH&HP) prostrated on earth.
Prophet Muhammad (PBUH&HP) and a Sajdah place other than earth
Looking carefully into Prophet Muhammad's (PBUH&HP) tradition, we realize that besides earth, one is also permitted to prostrate on plants, which grow from the earth and are not used as food or elements of clothing. The following Hadith illustrates the fact that Prophet Muhammad (PBUH&HP) would sometimes prostrate on certain sections of plants: Abu Sa'eed Khidri has narrated, "I once found Prophet Muhammad (PBUH&HP) doing Salat on a Mat (a small piece of carpet made by certain stems and leaves of plants) and prostrating on it (8)."
Anas ibn Malik has also narrated that the Prophet used to perform his Salat on a mat: "Once the Prophet was invited to lunch. After having lunch, he addressed us to pray. We cleaned a piece of Mat. Them he stood on it, began his Salat, and we accompanied him." (9)
Another thing Prophet Muhammad (PBUH&HP) would prostrate on in Salat was a "Khumrah". Khumrah is a small carpet made from the branches of a palm tree, and is used to put one's forehead on in Sajdah. (10) Ibn Abbas, Ibn Umar and also Umm Salamah, Meymunah, and Aisha (who were the Prophet's wives) have all narrated that Prophet Muhammad (PBUH&HP) would also pray on Khumrah; (11) at times the Prophet would even assign someone to bring a Khumrah to the mosque so that he could pray on it. (12)
From the above statements one can conclude that Prophet Muhammad (PBUH&HP) would prostrate on items such as earth, stone, or parts of plants that are neither edible nor wearable.
The Companions' place of Sajdah
This act and practice of Prophet Muhammad (PBUH&HP) was so obvious that even the companions would prostrate on either earth or parts of some plants; and they would refrain from prostrating on man-made materials. For example, Jabir ibn Abdullah al-Ansari has narrated, "On one extremely burning midday, I was performing Salat with the Prophet. I took some gravel and held it in my hand; I then passed it over to my other hand in order to cool it. Once it was cooled, I prostrated on it." (13)
Bayhaqi, a well-known Sunni scholar, comments on the above stated Hadith as follows:" If indeed it was permissible to prostrate on cloth, it would have been much easier than cooling the gravel in order to prostrate on..." (14)
This Hadith and other similar ones clarify that it is not permissible to prostrate on cloth under normal situations.
Up to this point, only a small portion of the narrations about the area of prostration, have been discussed.
According to the books held authentic by our Sunni brothers, and according to other narrations about the life and style of Prophet Muhammad (PBUH&HP), it can be concluded that the method the Shiites follow in Salat and prostration is consistent with the way of Prophet Muhammad's (PBUH&HP) tradition. As a matter of fact, Shiites set the preference for prostration on the earth over all other options. However, the majority of the sects within Islam, including our Sunni brothers, unfortunately neglect this important tradition of Prophet Muhammad (PBUH&HP).
The underlying purpose for prostrating in this way…
Besides all these facts, our Imams (PBUT) have somewhat explained the reason for performing Sajdah on earth and the parts of plants which are neither edible nor wearable.
When Imam Sadiq (PBUH) declared the regulations of prostration for Hisham ibn Hakam, Hisham asked about the reasons. Imam Sadiq (PBUH) replied: "Sajdah is showing humbleness for Allah; thus it is not possible to prostrate on things which is eaten or worn because the materialistic people are a servant of their own food and clothing; yet a person who prostrates, is worshiping Allah during prostration. That person should not therefore place his forehead on what the materialistic people worship (with which they have been misled). Furthermore, prostrating on earth is superior because it involves a greater humbleness towards Allah." (15)
A sacred Turbah, the best thing to prostrate on
Till this point, it has become clear that according to Prophet Muhammad's (PBUH&HP) tradition, earth is the best thing to prostrate on, and we are free to select the earth from any land. However, the Infallible Imams (PBUT) have declared the most sacred earth for us to prostrate on. It is a known fact that the earth of different lands possesses different qualities. Furthermore, according to the Islamic traditions the earths of certain lands are superior religiously and spiritually. The superiority of these lands may help us gain a better proximity with Allah (SWT) during our Salat. However, which earth does possess such superiority?
Following their Imams (PBUT), the Shiites endeavor to select the earth on which Prophet Muhammad (PBUH&HP) used to respect, smell, kiss, and protect. (16) According to the narrations narrated by all Muslims (including both Shiites and Sunnis), the Turbah of Imam Hussain (PBUH) was respected and blessed by Prophet Muhammad (PBUH&HP) even 50 years before the incident of Karbala and Imam Hussain's (PBUH) martyrdom. As the most authentic Sunni books have narrated, it was so that the angels brought some of this Turbah for Prophet Muhammad (PBUH&HP) by Allah's (SWT) order. (17)
Therefore, it is highly recommended, following Prophet Muhammad (PBUH&HP) that we perform Sajdah on the earth on which the shrine of Imam Hussain (PBUH) is placed upon. By this, one is seeking proximity towards Allah (SWT) by prostrating on the Turbah of a person who sacrificed his existence in the way of his beloved, Allah (SWT).