It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Refrain from attributing any statement to me except that of which you are certain, for whoever attributes a false statement to me should prepare his abode in Hell, and whoever speaks about the Noble Qur'an without knowledge should also prepare his abode in Hell."
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 2974