Musnad Abu Ya'la al-Mawsili 109:191

Sufyan ibn Waki' narrated to us, my father narrated to us, from Ubayd Allah, from Abu al-Malih, Jabir ibn Abdullah narrated to us, he said: Allah sent down the Scrolls of Ibrahim on the first night of Ramadan. The Torah was sent down to Musa on the sixth night of Ramadan. The Zabur was sent down to Dawud on the eighteenth night of Ramadan. The Quran was sent down to Muhammad, may Allah bless him and grant him peace, on the twenty-fourth night of Ramadan.