It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "O Abu al-Mundhir! Which verse in the Book of Allah that you have with you is the greatest?" I said: "Allah - there is no god except Him, the Ever-Living, the Sustainer of all existence" [Surah al-Baqarah: 255] . Then he (peace and blessings be upon him) struck (patted) my chest with his hand and said: "O Abu al-Mundhir! May your knowledge be a blessing for you." This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

Jundub (may Allah be pleased with him) narrates: I came to Madinah in pursuit of knowledge and entered the mosque, and I saw people gathered around a man. I asked: "Who is this?" The people said: "This is Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him)." When he got up (from the mosque) I followed him. He entered his house, and I knocked on the door. He came out, rebuked me and was harsh with me. (In my grief) I turned towards the Qiblah and said: "O Allah! We complain to You about them (the people of knowledge). We spend our wealth, we wear out our bodies, and we ride our mounts (from far away) in search of knowledge, yet when we meet them, they dislike us." At this he said: "If you give me respite until Friday, I will relate everything I heard from the Messenger of Allah (peace and blessings be upon him), and in this matter I will not fear the blame of any blamer." Then, when Thursday came, I went out early in the morning and saw that the roads were packed with people. I asked: "What has happened to the people today?" They said: "Perhaps you are a stranger here?" I said: "Yes." They said: "The leader of the Muslims, Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him), has passed away."