Man Lā Yaḥḍuruh al-Faqīh

Hadith 828
prostration
828 - قال الصادق عليه السلام: " السجود على الأرض فريضة وعلى غير ذلك سنة.
Hadith.828 - Imam Jafar ibn Muhammad Al-Sadiq (as) said: "Prostration (Sujood) on the earth is obligatory (fardh), while prostrating on other than that is a recommended practice (sunnah)."
Source: Shaykh Muḥammad b. ʿAlī al-Ṣaduq