It is narrated from Sayyiduna Jubayr bin Mut'im (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) stood at (the Masjid of) al-Khayf and said: "May Allah keep fresh and radiant the servant who heard my words, preserved them, and then conveyed them to those who did not hear them; for many a bearer of knowledge and understanding is not himself a faqih (one of deep understanding), and many convey knowledge to those who have more understanding than they. There are three things over which the heart of a believer does not harbour rancour (or treachery): sincerity of deeds for Allah, sincere counsel and obedience to those in authority, and holding fast to the community (jama'ah) of the Muslims; for their supplication (or call) protects them from behind." This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and it is one of the important principles according to the experts of hadith, although they did not record it. However, Imam Bukhari did take narrations in his Sahih from Nu'aym bin Hammad, who is one of the imams of Islam.