Man Lā Yaḥḍuruh al-Faqīh
Hadith 12921300 - وَ سَأَلَ عَمَّارٌ اَلسَّابَاطِيُّ ، أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ: عَنْ حَدِّ اَلطِّينِ اَلَّذِي لاَ يُسْجَدُ فِيهِ مَا هُوَقَالَ «إِذَا غَرِقَتْ فِيهِ اَلْجَبْهَةُ وَ لَمْ تَثْبُتْ عَلَى اَلْأَرْضِ.
Hadith.1300 - Ammar al-Sabati asked Imam Jafar ibn Muhammad Al-Sadiq (as) about the extent of wetness or mud that makes it unsuitable for prostration.
Imam (as) said: "When the forehead sinks into it and does not remain firm on the ground”.