From him, from Ali ibn Isma'il from Muhammad ibn Amr ibn Sa'id:
Abu Al-Hasan Al-Ridha, peace be upon him, said: "Do not prostrate upon barren land, nor upon tar, nor upon plaster."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 328