Hadith 1547
Abu Hurairah (May Allah be pleased with him) said:
وعن أبي هريرة رضي الله عنه أن النبي صلى الله عليه وسلم قال: "كفى بالمرء كذبًا أن يحدث بكل ما سمع" . ((رواه مسلم))
The Prophet (ﷺ) said, "It is enough for a man to prove himself a liar when he goes on narrating whatever he hears." [Muslim].
In plain words
It is enough to make a person a liar that he repeats everything he hears. Passing on every rumour, without checking, is itself a kind of lying.
Reference : Riyad as-Salihin 1547 In-book reference : Book 17, Hadith 37