It was narrated that Mughirah bin Shu'bah said:
The Messenger of Allah (ﷺ) said: '"Whoever narrates a Hadith from me thinking it to be false, then he is one of the two liars." (IT)
English reference (IT): Vol. 1, Book 1, Hadith 41 (IT)
Arabic reference (IT): Book 1, Hadith 43 (IT)