Musannaf Ibn Abi Shayba 1:818

Abu Bakr narrated to us, he said: Ibn Mubarak and Ibn Numayr narrated to us, from Zakariyya, from Ali ibn al-Aqmar, he said: Abu al-Duha was asked, "Does the person in a state of major ritual impurity (junub) eat?" He said: "Yes, and he walks in the marketplaces."