Musnad Ahmad 32:1037

Bahz ibn Asad narrated to us, Hammad ibn Salamah narrated to us, Thabit narrated to us, from Anas: That Usayd ibn Hudayr and Abbad ibn Bishr were with the Messenger of Allah, may Allah bless him and grant him peace, on a dark, pitch-black night. He said: When they left him, the staff of one of them lit up, and they were walking by its light. When they parted ways, the staff of this one lit up, and the staff of that one lit up.