Musannaf Ibn Abi Shayba 3:538

Abu Mu'awiyah narrated to us, from al-A'mash, from 'Umarah ibn 'Umayr, from al-Aswad, who said: 'Abdullah said: "Whoever among you is able not to let anyone pass in front of him while he is praying, then let him do so; for the one passing in front of the person praying is more deficient than the one being passed in front of."