Musnad Ahmad 30:757

Al-Fadl narrated to us, Sufyan narrated to us, from Salih ibn Nabhan, from Abu Hurairah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Do not hate one another, do not outbid one another (to deceive), do not envy one another, and be, O servants of Allah, brothers."