The House of Al-Arqam
In the light of these inhuman persecutions, the Prophet [pbuh] deemed it wise to advise his followers to conceal their conversion, in both word and deed. He took the decision to meet them secretly lest Quraish should get to know of his designs, and so take measures that might foil his goals. He also had in mind to avoid any sort of open confrontation with the polytheists because such a thing at this early stage would not be in the interest of the newly-born Call, still vulnerable and not fully fledged. Once, in the fourth year of Prophethood, the Muslims were on their way to the hillocks of Makkah to hold a clandestine meeting with the Prophet [pbuh], when a group of polytheists did observe their suspicious movement and began to abuse and fight them. Sa‘d bin Abi Waqqas beat a polytheist and shed his blood and thus recorded the first instance of bloodshed in the history of Islam. [Ibn Hisham 1/263]
The Prophet [pbuh], on the other hand, used to proclaim the Islamic Faith and preach it openly with deep devotion and studious pursuit, but for the general welfare of the new converts and in consideration of the strategic interest of Islam, he took Dar Al-Arqam, in As-Safa mountain, in the fifth year of his mission, as a temporary centre to meet his followers secretly and instruct them in the Qur’ân and in the Islamic wisdom.