Musnad Ahmad 25:821

Hassan narrated to us, Hammad bin Salamah narrated to us, from Ammar bin Abi Ammar, from Ibn Abbas: "The Messenger of Allah (peace and blessings of Allah be upon him) stayed in Makkah for fifteen years. For eight or seven years, he would see the light and hear the sound, and for eight or seven years, revelation was sent down to him. And he stayed in Al-Madinah for ten years."