Musnad Ahmad 32:1711

'Affan narrated to us, Hammad narrated to us, he said: Thabit informed us, from Anas, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "O assembly of the Ansar, did I not come to you while you were astray, so Allah guided you through me, and as enemies, so Allah brought your hearts together through me?" Then he said to them: "Will you not say: You came to us driven away, so we gave you shelter; and afraid, so we gave you security; and forsaken, so we gave you victory?" They said: "Rather, the favor is Allah's and His Messenger's upon us."