Musnad Abu Ya'la al-Mawsili 4:2

Ubayd Allah narrated to us, Umar ibn Ubayd al-Tanafisi narrated to us, from Simak ibn Harb, from Musa ibn Talhah, from his father, who said: We used to pray while the animals would pass in front of us. We mentioned that to the Prophet, may Allah bless him and grant him peace, and he said: "Let something like the back of a saddle be in front of one of you, then it will not harm him what passes in front of him."