Musannaf Ibn Abi Shayba 16:594

Abu Bakr narrated to us, he said: Affan narrated to us, he said: Wuhayb narrated to us, he said: Dawud ibn Abi Hind narrated to us, from Abu Qaza'ah, from al-Asqa' ibn al-Asla', from Samurah ibn Jundub, from the Prophet (peace be upon him), he said: "Whatever is below the two ankles of the lower garment is in the Fire."