Musannaf Ibn Abi Shayba 9:1766

Humaid ibn Abd al-Rahman narrated to us, from Hasan, from Ibn Abi Layla, from Abd al-Karim, from Mujahid, that he disliked the marriage of the Christian women of the Romans who are not of the people of the covenant (Ahl al-Ahd). He said: Muhammad described the man who is a commander and wishes to marry, so he (Mujahid) disliked that for him.