Musnad Abu Ya'la al-Mawsili 116:50

Ahmad narrated to us, Wahb bin Jarir narrated to us, Shu'bah narrated to us, from Qatadah and Abu al-Tayyah, from Anas, that the Messenger of Allah (may Allah bless him and grant him peace) said: "I and the Hour have been sent like these two," meaning the index finger and the middle finger.