The Prophet ﷺ said, "Whoever narrates a hadith from me while believing it to be false is himself one of the liars."
حدثنا أبو بكر بن أبي شيبة حدثنا علي بن هاشم عن ابن أبي ليلى عن الحكم عن عبد الرحمن بن أبي ليلى
عن النبي ﷺ قال من حدث عني حديثا وهو يرى أنه كذب فهو أحد الكاذبين
Sourcing, sahih. Reported by Ibn Abu Shayba, Al-Adab, chapter on what is mentioned regarding the signs of hypocrisy, 8/595, no. 25607. Ibn Abu Layla was corroborated by Shuba in one narration and by Amash, and the hadith that follows serves as supporting evidence for it. See also no. 40.