AYATOLLAH ABUL QASIM AL KHOI

1093. If a person does not possess anything on which it is lawful to perform prostration or, even if he does posses such a thing but cannot perform prostration on it on account of severe heat or coldness, he should perform prostration on his dress and if even this is not possible he should perform prostration on the back of his hand or on any other thing on which it is not permissible to perform prostration optionally. However, the recommended precaution is that so long as it is possible to perform prostration on the back of one's hand it should not be performed on any other such thing.

AYATOLLAH SYED ALI SISTAANI

1093. * If a person does not possess anything on which it is allowed to perform Sajdah, or, even if he possesses such a thing, he cannot perform Sajdah on it due to severe heat or cold, he should perform Sajdah on asphalt or tar, and if that is not possible, on his dress or the back of his hand, or on any thing on which it is not permissible to perform Sajdah optionally. However, in such a situation, the recommended precaution is that as long as it is possible to perform Sajdah on his dress he should not do Sajdah on any other thing.

AYATOLLAH SYED MOHAMMED RAZA MOOSVI GULPAYEGANI

1093. * If a person does not possess anything on which it is allowed to perform Sajdah, or, even if he possesses such a thing, he cannot perform Sajdah on it due to severe heat or cold, he should perform Sajdah on his dress if it is made of Alsi, cotton and if it is made of something else then on the back of his hand, or on any thing which is mined for example ring of Haqeeq. However, in such a situation, the recommended precaution is that as long as it is possible to perform Sajdah on back of his hand he should not do Sajdah on any other mined thing.

IMAM KHOMEINI

1074. * Sajdah is done on anything which is grown from the earth and not used for eating.  For example wood, leaves of trees. And it is not allowed to perform Sajdah on the things which are eatable and wearable. Nor on the mined things, for example, Gold, Silver, Haqeeq, Ferozah on which the Sajdah is forbidden. Left is the mined stones, such as Marble or Black Stone there is no problem to perform Sajdah on it.

1082. * If a person does not possess anything on which it is allowed to perform Sajdah, or, even if he possesses such a thing, he cannot perform Sajdah on it due to severe heat or cold, he should perform Sajdah on his dress if it is made of Alsi, cotton and if it is made of something else also and if not on it then on the back of his hand, and if it is also not possible then on any thing which is mined for example ring of Haqeeq.

TRADITION OF THE INFALLIBLES AS

Hasham bin Hakam asked Imam Jaffer Sadiq AS about the things on which Sajdah is permissible and forbidden? Imam AS replied, “Sajdah is forbidden except on earth or anything which are grown form it, except those things which are eatable or wearable. He asked be I gets sacrificed on you, what is the reason for it? Imam replied “it is because the Sajdah is bowing to thy Lord and it is forbidden for a person to bow on eatable and wearable things since the people have become slaves of the eatable and wearable things, and the person who perform Sajdah is actually busy in worshipping Allah and it is not permissible to put your forehead on the things which are the Lords of the people of the world and they have been betrayed by it. And it is better to do sajdah on earth because this is the way to show your will and gratitude towards Allah”