Musnad Ahmad 1012:32

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Qatadah, who said: I heard Anas ibn Malik narrating from 'Ubadah ibn as-Samit, from the Prophet, may Allah bless him and grant him peace, that he said: "The dream of a Muslim is one part out of forty-six parts of prophethood."