Chapter on the Description of Ablution (Wudu)
Tahdhīb al-Aḥkām|Volume 1|Book 1|Chapter 4
فَأَمَّا اَلْخَبَرُ اَلَّذِي رَوَاهُ اَلْحُسَيْنُ بْنُ سَعِيدٍ عَنْ حَمَّادٍ عَنْ يَعْقُوبَ عَنْ مُعَاوِيَةَ بْنِ وَهْبٍ قَالَ: سَأَلْتُ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ عَنِ اَلْوُضُوءِ فَقَالَ« مَثْنَى مَثْنَى».
As for the report narrated by al-Husayn ibn Saʿid, from Hammad, from Yaʿqub, from Muawiyah ibn Wahb, who said:
I asked Abu Abdullah عليه السلام about ablution (Wuduʾ), and Imam عليه السلام said: "Twice for each part."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 83
- Ṣaḥīḥ al-Tahdhīb