Musannaf Ibn Abi Shayba 16:589

Abu Bakr narrated to us, he said: Ya'la narrated to us, from Muhammad ibn Ishaq, he said: I heard Abu Nabih saying: I heard 'Aisha saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whatever is below the ankles of the lower garment is in the Fire."