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.'" (DE)
English reference (DE): Vol. 1, Book 1, Hadith 456 (DE)
Arabic reference (DE): Book 1, Hadith 492 (DE)