Musnad Ahmad 30:909

'Abd al-Rahman and Mu'ammal narrated to us, they said: Zuhayr ibn Muhammad narrated to us - Mu'ammal said: al-Khurasani - Musa ibn Wardan narrated to us, from Abu Hurayrah, he said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "A person is upon the religion of his close friend, so let one of you look at whom he associates with." And Mu'ammal said: "Whom he takes as a close friend."