Hadith 7134
Sayyiduna Abu Dharr Ghifari (may Allah be pleased with him) narrates: I was the fourth person to accept Islam; before me, three people had accepted Islam and I was the fourth. I presented myself before the Prophet (peace and blessings of Allah be upon him) and said: O Messenger of Allah (peace and blessings of Allah be upon him), peace be upon you. I bear witness that there is no deity except Allah, and I bear witness that Sayyiduna Muhammad (peace and blessings of Allah be upon him) is His servant and His Messenger. I saw signs of happiness on the blessed face of the Prophet (peace and blessings of Allah be upon him). He asked: Who are you? I replied: My name is Jundub and I am a person from Banu Ghifar.
(Imam Ibn Hibban, may Allah have mercy on him, says:) The statement of Sayyiduna Abu Dharr Ghifari (may Allah be pleased with him): "I was the fourth person to accept Islam," means that he was the fourth person from his tribe to accept Islam, because at that time, many people from the Quraysh and other tribes had already become Muslim.