Musnad Ahmad 32:1801

Husayn ibn Muhammad narrated to us, Sufyan—meaning Ibn ‘Uyaynah—narrated to us, from ‘Ali ibn Jad’an, from Anas, that the Messenger of Allah (may Allah bless him and grant him peace) said: "The voice of Abu Talhah in the army is better than a battalion." He said: And he used to kneel before him in battle, then scatter his quiver, and say: "My face is a shield for your face, and my soul is a ransom for your soul."