Chapter on What is Permissible to Pray in, from Clothing and Place, and What is Not Permissible to Pray in, from That

And Hisham ibn Al-Hakam said to Abu Abdillah عليه السلام: “Inform me about what is permissible to prostrate upon and what is not permissible.” Imam عليه السلام said: “Prostration is not permissible except upon the earth or that which the earth grows, except what is eaten or worn.”