Narrated Abdullah ibn Abbas (may Allah be pleased with them both): When Abu Dharr (may Allah be pleased with him) learned about the Prophethood of Allah’s Messenger (peace and blessings be upon him), he said to his brother Anis,“Prepare a mount for me to go to Makkah, and gather information for me about the man who claims to be a Prophet and says that news comes to him from the sky. Listen carefully to what he says and then come back to me.”His brother went there, arrived in Makkah, listened to the words of the Prophet (peace and blessings be upon him) himself, and then returned and told Abu Dharr (may Allah be pleased with him),“I have seen him myself. He enjoins people to good character, and the words I heard from him are not poetry.”Upon this, Abu Dharr (may Allah be pleased with him) said,“I am not fully satisfied with what I sent you for.”So he packed his provisions, took an old water-skin filled with water, and came to Makkah. He attended Masjid al-Haram and began searching for the Prophet (peace and blessings be upon him). Abu Dharr (may Allah be pleased with him) did not recognize the Prophet (peace and blessings be upon him), nor did he consider it appropriate to ask anyone about him. Some of the night passed while he was lying down. Ali (may Allah be pleased with him) saw him in that state and realized he was a traveler. Ali (may Allah be pleased with him) said to him,“Come to my house and rest.”Abu Dharr (may Allah be pleased with him) followed him, but neither of them spoke to the other about anything. When morning came, Abu Dharr (may Allah be pleased with him) picked up his water-skin and provisions and went to Masjid al-Haram. That day also passed in the same way, and he could not see the Prophet (peace and blessings be upon him). Evening came, and he prepared to sleep. Ali (may Allah be pleased with him) again passed by and realized that this person had not yet found his destination. He again took him with him, and again, neither of them spoke to the other. On the third day, Ali (may Allah be pleased with him) did the same and took him with him. Then he asked,“Can you tell me the reason for your coming here?”Abu Dharr (may Allah be pleased with him) said,“If you make a firm promise to guide me, I will tell you everything.”Ali (may Allah be pleased with him) promised, so he informed him of his thoughts. Ali (may Allah be pleased with him) said,“Indeed, he is upon the truth and is Allah’s true Messenger. In the morning, follow me closely. If I see anything on the way that makes me fear for you, I will stop (near a wall) as if to urinate. At that time, do not wait for me, but when I start walking again, follow me, so that no one realizes that we are together. In this way, whichever house I enter, you also enter.”He did so and followed behind until, with Ali (may Allah be pleased with him), he reached the service of the Prophet (peace and blessings be upon him), listened to his words, and accepted Islam there. Then the Prophet (peace and blessings be upon him) said to him,“Now return to your tribe Ghifar and inform them about me. When you hear of our dominance, then come to us.”Abu Dharr (may Allah be pleased with him) said,“By Him in Whose hand is my soul! I will proclaim the testimony of faith in the gathering of the Quraysh.”So, after leaving the Prophet (peace and blessings be upon him), he came to Masjid al-Haram and proclaimed in a loud voice,“I bear witness that there is no god but Allah and that Muhammad (peace and blessings be upon him) is Allah’s Messenger.”As soon as they heard this, the whole gathering rushed at him and beat him so much that he was thrown to the ground. Meanwhile, Abbas (may Allah be pleased with him) came and threw himself over Abu Dharr (may Allah be pleased with him) and said to the Quraysh,“Woe to you! Do you not know that this man is from the tribe of Ghifar, and your trade route to Syria passes through them?”In this way, he saved him from them. Then Abu Dharr (may Allah be pleased with him) came to Masjid al-Haram the next day and again declared his Islam. The people again rushed at him and began to beat him severely. That day too, Abbas (may Allah be pleased with him) threw himself over him.