(9) باب وُجُوبِ غَسْلِ الرِّجْلَيْنِ بِكَمَالِهِمَا
Salim, the freed slave of Shaddad, said:
I came to 'A'isha, the wife of the Prophet (ﷺ), on the day when Sa'db. Abi Waqqas died. 'Abd al-Rahman b. Abu Bakr also came there and he performed ablution in her presence. She (Hadrat 'A'isha) said: Abd al-Rahman, complete the ablution as I heard the Allah's Messenger (ﷺ) say: Woe to the heels because of hell-fire.
Reference: Sahih Muslim 240a
In-book reference: Book 2, Hadith 33
USC-MSA web (English) reference(deprecated numbering scheme): Book 2, Hadith 464