Musannaf Ibn Abi Shayba 36:132

Waki’ narrated to us, from Isra’il, from Abu Ishaq, from Harithah ibn Mudarrib, from Ali, who said: I have seen us on the day of Badr, and we were seeking refuge with the Messenger of Allah, may Allah bless him and grant him peace, and he was the closest of us to the enemy.