Masruq (may Allah have mercy on him) says that once I was sitting with Sayyiduna Ibn Amr (may Allah be pleased with him). He began mentioning Sayyiduna Ibn Mas'ud (may Allah be pleased with him) and said: "He is such a man whom I will always love. I heard the Noble Prophet (peace and blessings be upon him) say: 'Learn the Qur'an from four people,' and he mentioned Sayyiduna Ibn Mas'ud (may Allah be pleased with him) first, then Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him), then Salim (may Allah be pleased with him), the freed slave of Sayyiduna Abu Hudhaifah (may Allah be pleased with him), and Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him)."