Musannaf Ibn Abi Shayba 35:131

'Abdah narrated to us, from Ibn Abi 'Arubah, from Sulayman al-Naji, from Abu al-Mutawakkil, from Abu Sa'id, who said: A man came while the Prophet (peace be upon him) had already prayed. The Prophet (peace be upon him) said to him: "Who among you will trade with this [man]?" He said: So a man from the people stood up and prayed with him. And he mentioned that Abu Hanifah said: "Do not congregate in it."