It is narrated from Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever conceals knowledge, Allah will bridle him on the Day of Resurrection with a bridle of fire." This is an authentic chain from the narration of the Egyptians, on the condition of the two Shaykhs (Bukhari and Muslim), and there is no hidden defect ('illah) in it. In this chapter there is also a group of Companions besides Abu Hurayrah.