It was narrated from 'Ali that:
The Prophet (ﷺ) said: '"Whoever narrates a Hadith from me thinking it to be false, then he is one of the two liars." (Either the one who invents a lie or the one who repeats it; both are liars).
English reference: Vol. 1, Book 1, Hadith 38
Arabic reference: Book 1, Hadith 39