Chapter on the Description of Ablution (Wudu)
Tahdhīb al-Aḥkām|Volume 1|Book 1|Chapter 4
مَارُوِيَ عَنِ اَلنَّبِيِّ صَلَّى اَللَّهُ عَلَيْهِ وَآلِهِ: أَنَّهُ طَافَ وَخَرَجَ مِنَ اَلْمَسْجِدِ فَبَدَأَ بِالصَّفَا وَقَالَ« اِبْدَءُوا بِمَا بَدَأَ اَللَّهُ بِهِ».
It is narrated from the Prophet صلى الله عليه وعلى آله وسلم that He صلى الله عليه وعلى آله وسلم performed Tawaf, exited the mosque, and began at al-Ṣafa, saying: "Begin with what Allah سبحانه وتعالى began with."
- Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 1, p. 100
- Ṣaḥīḥ al-Tahdhīb