Musnad Ahmad 32:81

Ibn Abi ‘Adi narrated to us, from Humayd, 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, and Allah guided you through me? Did I not come to you while you were divided, and Allah united you through me? Did I not come to you while you were enemies, and Allah brought your hearts together through me?" They said: "Indeed, O Messenger of Allah." He said: "Will you not say: 'You came to us fearful, so we secured you; and an outcast, so we sheltered you; and forsaken, so we aided you'?" They said: "Rather, the favor is Allah’s upon us, and His Messenger’s."