What Defiles Clothing and the Body
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 17
وَ سَأَلَ إِبْرَاهِيمُ بْنُ أَبِي مَحْمُودٍ اَلرِّضَا عَلَيْهِ اَلسَّلاَمُ: عَنِ اَلطِّنْفِسَةِ وَ اَلْفِرَاشِ يُصِيبُهُمَا اَلْبَوْلُ كَيْفَ يُصْنَعُ وَ هُوَ ثَخِينٌ كَثِيرُ اَلْحَشْوِ فَقَالَ «يُغْسَلُ مِنْهُ مَا ظَهَرَ فِي وَجْهِهِ.
Ibrahim ibn Abi Mahmoud asked Imam Ali ibn Musa Ar-Ridha عليه السلام about rug (al tanfasah) or mattress (al firash) that is affected by urine, especially if it is thick and heavily padded. Imam عليه السلام said: 'You should wash the surface that is visible.'.
- Ṣaḥīḥ al-Faqīh