“O you who believe! If a Faasiq (liar) comes to you with any news, verify it, lest you should harm people in ignorance, and afterwards you become regretful for what you have done”
(al Hujrat 49:6)

Narrated by Hazrat Hafs ibn ‘Aasim: The Messenger of Allah Sallal lahu alaihi wasallam said: “He is also a liar who speaks everything he hears.”  Saheeh al-Jaami, 4482; Mishkawt.