Musannaf Ibn Abi Shayba 33:596

Ghundar narrated to us, from Shu'bah, from Ziyad ibn Mikhraq, from Abu Iyas, from Abu Kinanah, from Abu Musa al-Ash'ari, that he said: "Indeed, this Qur'an will be a reward for you, and it will be a reminder for you, and it will be a burden upon you. So follow the Qur'an, and do not let the Qur'an follow you; for whoever follows the Qur'an, it will descend with him upon the gardens of Paradise. And whoever the Qur'an follows, it will push him in the nape of his neck and cast him into Hell."