Musnad Ahmad 30:2863

'Affan narrated to us, he said: Hammad narrated to us, from Muhammad ibn Ziyad and 'Ammar ibn Abi 'Ammar, from Abu Hurairah, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Men will surely depart from Medina, desiring what is away from it, and Medina is better for them if they only knew."