Man Lā Yaḥḍuruh al-Faqīh
Hadith 158159 - 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.
Hadith.159 - Ibrahim ibn Abi Mahmoud asked Imam Ali ibn Musa Ar-Ridha (as) about rug (al tanfasah) or mattress (al firash) that is affected by urine, especially if it is thick and heavily padded.
Imam (as) said: 'You should wash the surface that is visible.'.