It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "I fear nothing for my Ummah except weakness of certainty."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Sayyiduna Abu Hurayrah (may Allah be pleased with him) except Abd al-Rahman bin Buzruj, and Sa'id bin Abi Ayyub is alone in narrating it."