Musannaf Ibn Abi Shayba 17:1247

Yahya ibn Adam narrated to us, he said: Isra'il narrated to us, from Abu Ishaq, from al-Bara', who said: The Messenger of Allah (may Allah bless him and grant him peace) passed by a gathering of the Ansar and said: "If you refuse [to do anything] but to sit, then guide the way and help the oppressed."