It was narrated that Abu Haiyah said:
"I saw 'Ali performing ablution and he washed his feet up to the ankles, then he said: 'I wanted to show you how your Prophet purified himself.'" (IT)
English reference (IT): Vol. 1, Book 1, Hadith 456 (IT)
Arabic reference (IT): Book 1, Hadith 492 (IT)