Imam Tawus, may Allah have mercy on him, said: Bishr bin Ka’b came to Sayyiduna Abdullah bin Abbas, may Allah be pleased with them both, and began narrating hadith. Sayyiduna Ibn Abbas, may Allah be pleased with them both, said: Recite the first hadith to me again. Bishr said to him: I do not know whether you considered all my ahadith to be correct except the first one, or you considered the first hadith to be correct and the rest not correct? Sayyiduna Ibn Abbas, may Allah be pleased with them both, said: We used to narrate hadith from the Messenger of Allah, peace and blessings be upon him, at a time when lies were not attributed to him. Then, when people became involved in both truth and falsehood (i.e., mixing lies with truth), we stopped narrating hadith from him. (That is, when people began attributing lies to the Messenger of Allah, peace and blessings be upon him, we became cautious and began to investigate the narrator.)