Musnad Ahmad 30:881

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, I heard al-‘Ala’ narrating from his father, from Abu Hurayrah: That the Prophet, may Allah bless him and grant him peace, narrates it from his Lord, the Almighty and Majestic, that He said: "I am the best of partners. So whoever performs a deed in which he associates someone else with Me, then I am free of him, and it is for the one whom he associated [with Me]."