Turbah

A turbah (Arabic: تربة, lit. 'soil'), or mohr (Persian: مهر, lit. 'seal'), also known as khāk-e shefā (Persian: خاکِ شِفا, lit. 'medicinal soil', also used in Urdu) and sejde gāh (Persian: سجدہ گاہ, lit. 'place of prostration', also used in Urdu), is a small piece of soil or clay, often a clay tablet, used during salat (Arabic: صلاة, lit. 'Islamic daily prayers') to symbolize earth. The use of a turbah is recommended (Arabic: مُسْتَحَبّ, romanized: mustahabb, lit. 'beloved') according to the Twelver Shia school of Islam, a unique practice of the sect, and many ahadith mention the benefits of prostration (Arabic: سجدة, romanized: sajdah) upon soil or an alternative natural material. The most recommended soil is that of Karbala, the site of the martyrdom of Husayn ibn 'Ali; however, soil from anywhere may be used. In the absence of soil, plants or items made from these may be substituted. This provision has been extended to include paper.

Following instruction from the Qur’an, the Shia Imam Ja'far al-Sadiq stated that "prostration must be performed on pure earth or what grows on it, provided that it is not eaten or worn." (like leaves, wood, stone/marble so on). For example, prostration on paper is permissible because it is made of natural elements grown on earth.