Chapter on Water and Its Rules
Tahdhīb al-Aḥkām|Volume 1|Book 1|Chapter 21
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ هِشَامِ بْنِ الْحَكَمِ عَنْ أَبِي عَبْدِ اللهِ عَلَيْهِ السَّلَامُ فِي مِيزَابَيْنِ سَالَا أَحَدُهُمَا بَوْلٌ وَالْآخَرُ مَاءُ الْمَطَرِ فَاخْتَلَطَا فَأَصَابَ ثَوْبَ رَجُلٍ، لَمْ يَضُرَّهُ ذٰلِكَ.
Ali ibn Ibrahim, from his father, from Ibn Abi Umair, from Hisham ibn Al-Hakam: Abu Abdullah عليه السلام was asked regarding two spouts - one carrying urine and the other carrying rainwater - that flowed and mixed, and then splashed onto a man's clothing. Imam عليه السلام said: "It does not harm him."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 436
- Ṣaḥīḥ al-Tahdhīb