Musannaf Ibn Abi Shayba 17:1019

'Abd al-Rahim ibn Sulayman narrated to us, from Hajjaj, from 'Amr ibn Shu'ayb, from his father, from his grandfather, that the Prophet (may Allah bless him and grant him peace) passed by some people who were shooting [arrows]. He said, "Shoot, and I am with the son of al-Adra'." They said, "O Messenger of Allah, shall we shoot while you are with some of us and not others?" He said, "Shoot, and I am with all of you, O sons of Ishmael."