Musnad Ahmad 27:666

Abu al-Nadr narrated to us, Abd al-Rahman ibn Thabit ibn Thawban narrated to us, Hassan ibn Atiyyah narrated to us, from Abu Munib al-Jurashi, from Ibn Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "I was sent before the Hour with the sword, until Allah is worshipped alone with no partner, and my provision was placed under the shadow of my spear, and humiliation and lowliness were placed upon those who oppose my command. And whoever imitates a people, he is one of them."