Malik related to me from Abd ar-Rahman ibn Harmala that Said ibnal-Musayyab heard the Messenger of Allah, may Allah bless him andgrant him peace, say, "Shaytan concerns himself with one and two. Whenthere are three, he does not concern himself with them."
USC-MSA web (English) reference: Book 54, Hadith 36
Arabic reference: Book 54, Hadith 1802