Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: Indeed, this Qur'an is an intercessor whose intercession will be accepted. Whoever follows it, it will lead him to Paradise; and whoever abandons it (the narrator is unsure; or perhaps the words are:) whoever turns away from it (the narrator is unsure; or perhaps it was some other similar word), he will be driven by the back of his neck towards Hell.
Al-Bazzar recorded it in this way as mawquf (a statement of) Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب العلم / 791