Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) says that he heard the Messenger of Allah (peace and blessings be upon him) say: "Among the greatest of lies are three: that a man lies about his eyes, saying 'I have seen' when he has not seen; that he lies by ascribing himself to someone other than his father; or that he says 'I heard it with my own ears' when he has not heard."
Hadith Referenceالمعجم الكبير للطبراني / باب الواو / 18384