When Abu Dharr received the news that a Prophet had manifested himself in Makkah, he instructed his brother Anis to go and acquire some information about him.
His brother went to Makkah, came back and described the Noble Prophet (S) to him.
“You have not been able to smother the flames that smolder within my heart,” Abu Dharr complained.
He therefore made arrangements to undertake a journey to Makkah. On his arrival there, he took shelter in one corner of a mosque till on the third day, under the guidance of ‘Ali (as), he covertly approached the Noble Prophet (S) and greeted him.
When the Noble Prophet (S) asked him his name and inquired about him, Abu Dharr gave him the answers, following which he accepted Islam.
The Noble Prophet (S) advised him: “Return to your city and do not stay in Makkah for I fear that you might be subjected to persecution (here).”
“By He, in Whose Hand lies my soul! I shall shout out in front of the people and loudly proclaim my acceptance of Islam,” responded Abu Dharr.
He headed straight towards Masjidul Haram where in a loud voice, he testified to the Unity of Allah and the Prophethood of the Noble Prophet (S). Hearing this, the people of Makkah rushed towards him to beat him up till he dropped down, unconscious. As ‘Abbas, the paternal uncle of the Noble Prophet (S) witnessed the scene, he threw himself upon Abu Dharr and shouted out to the people: “O’ People! Woe unto you! Do you not see that this person is from the tribe of Ghaffar and was amidst you while on a journey towards Syria?” With these words, he managed to save Abu Dharr’s life.
The next day, his condition improved but Abu Dharr again proclaimed his new faith and was badly beaten up once more. For the second time in as many days, ‘Abbas intervened and saved him from their beatings. After this, Abu Dharr left Makkah and returned to his city. ( Paighambar Wa Yaran, Volume 1, Page 45; A’yan al-Shi’a, Page 316 )