It is narrated from Sayyiduna Abu Shurayh al-Khuza'i (may Allah be pleased with him); he said: The Messenger of Allah (peace and blessings be upon him) came out to us and said: "Rejoice! Do you not bear witness that there is no god worthy of worship except Allah and that I am the Messenger of Allah?" We said: Certainly. He (peace and blessings be upon him) said: "Indeed, this Qur'an is a rope, one end of which is in the Hand of Allah and the other end in your hands. So hold fast to it, for after it you will never go astray and you will never perish."
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18711