Musnad Abu Ya'la al-Mawsili 115:153

Muhammad ibn al-Muthanna narrated to us, Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, he said: I heard Qatadah narrating from Anas, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The Ansar are my inner circle and my trusted confidants. Indeed, people will increase, and they will decrease. So accept from their doers of good, and pardon their wrongdoers."