Musannaf Ibn Abi Shayba 22:143

Abu Khalid al-Ahmar narrated to us, from ‘Amr ibn Qays, from Zubayd, who said: ‘Abdullah said: The Qur’an is an intercessor whose intercession is accepted, and an accuser whose testimony is believed. Whoever places it in front of him, it will lead him to Paradise. And whoever places it behind his back, it will lead him to the Fire.