Abd Khayr reported,

I came to Ali after he had already prayed, and he called for water for purification.We said, "What is he doing with water for purification when he has already prayed? He only intends to teach us."A basin and a vessel were brought. He lifted the vessel and poured water over his hand, washing it three times. Then he dipped his hand into the vessel, rinsed his mouth, and sniffed water into his nose three times. He rinsed his mouth and blew the water out from the same handful he had taken. Then he washed his face three times, washed his right hand three times, and his left hand three times. Then he placed his hand in the water and wiped his head once. Then he washed his right foot three times, and his left foot three times.Then he said, "Whoever wishes to know how the Messenger of Allah ﷺ performed his purification, this is it."

حدثنا عفان أراه عن أبي عوانة عن خالد بن علقمة

عن عبد خير قال

أتيت عليا رضي الله عنه وقد صلى فدعا بطهور فقلنا ما يصنع بالطهور وقد صلى ما يريد إلا أن يعلمنا فأتي بطست وإناء فرفع الإناء فصب على يده فغسلها ثلاثا ثم غمس يده في الإناء فمضمض واستنثر ثلاثا ثم تمضمض وتنثر من الكف الذي أخذ منه ثم غسل وجهه ثلاثا وغسل يده اليمنى ثلاثا ويده الشمال ثلاثا ثم جعل يده في الماء فمسح برأسه مرة واحدة ثم غسل رجله اليمنى ثلاثا ورجله الشمال ثلاثا ثم قال من سره أن يعلم طهور رسول الله ﷺ فهو هذا