Musannaf Ibn Abi Shayba 1:268

Abu Mu'awiyah narrated to us, from al-A'mash, from Abu Sufyan, from Jabir, who said: The Prophet, may Allah bless him and grant him peace, saw some people who performed ablution, but the water did not reach their heels. The Prophet, may Allah bless him and grant him peace, said: "Woe to the heels from the Fire."