It is narrated from Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) that he said: "I narrate to the people the hadiths of the Messenger of Allah (peace and blessings be upon him), and they talk of this and that. If I die, they will then not hear anyone saying: 'I heard the Messenger of Allah (peace and blessings be upon him) say.'" This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.