Musannaf Ibn Abi Shayba 35:64

Abu Khalid al-Ahmar narrated to us, from Hajjaj, from ‘Amr ibn Shu‘ayb, from his father, from his grandfather, that the Prophet (peace and blessings of Allah be upon him) combined two prayers during the expedition of Banu al-Mustaliq. And he mentioned that Abu Hanifah said: "It is not sufficient for him to do that."