Sahih Bukhari
Virtues and Merits of the Prophet (pbuh) and his Companions
Volume: 004 / Book Number: 056 / Hadith Number: 712
Narrated Wathila bin Al-Asqa:
Allah's Apostle said, "Verily, one of the worst lies is to claim falsely to be the son of someone other than one's real father, or to claim to have had a dream one has not had, or to attribute to me what I have not said."