Chapter on the Description of Ablution (Wudu)
Tahdhīb al-Aḥkām|Volume 1|Book 1|Chapter 4
وَ بِهَذَا اَلْإِسْنَادِ عَنْ سَهْلِ بْنِ زِيَادٍ عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَبْدِ اَلْكَرِيمِ قَالَ: سَأَلْتُ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ عَنِ اَلْوُضُوءِ فَقَالَ« مَا كَانَ وُضُوءُ عَلِيٍّ عَلَيْهِ اَلسَّلاَمُ إِلاَّ مَرَّةً مَرَّةً
Through the same chain of transmission, from Sahl ibn Ziyad, from Ahmad ibn Muhammad, from Abd al-Karim, who said:
I asked Abu Abdullah عليه السلام about ablution (Wuduʾ), and Imam عليه السلام said: "The ablution of (Imam) Ali عليه السلام was only once for each part."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 83
- Ṣaḥīḥ al-Tahdhīb