Musannaf Ibn Abi Shayba 3:5869

Bakr ibn Abd al-Rahman narrated to us, he said: Isa ibn al-Mukhtar narrated to us, from Ibn Abi Layla, from Abu Qays, from Huzayl, from Abdullah ibn Mas’ud, that the Prophet, peace and blessings of Allah be upon him, combined the two prayers while traveling.