The Prophet...
The Prophet, therefore, started his mission cautiously, confining it initially to his own close relatives and friends. He was met with immediate success. His wife Khadijah testified to his truth as soon as she heard the news of the revelation from God. Then his cousin 'Ali, and his liberated slave and adopted son Zaid, readily accepted the new faith, Islam, "submission to the Will of God." The fourth was Abu Bala.
Ibn Hajar al-'Asqalani in his book Al-Isabah, and 'Abdul Malik ibn Hisham in his book As-Sirah have written that: "Ali was the first to accept Islam and pray (offer salat), and that he accepted whatever was revealed to the Messenger by the Lord. At that time, 'Ali was only ten years old. After 'Ali, Zaid ibn Harithah accepted the Islamic creed and prayed and then Abu Bakr embraced Islam.
The companions of the Holy Prophet, Muhammad ibn Ka'b al-Qarzi, Salman the Persian, Abu Dharr, Miqdad, Khabbab, Abu Sa'eed al-Khudri and Zaid ibn al-Arqam testify that 'Ali was the first to proclaim Islam.
These celebrated companions have given'Ali preference over others." Justice Ameer Ali writes in his Spirit of Islam: "It is a noble feature in the history of the Prophet of Arabia, and one which strongly attests the sincerity of his character, the purity of his teachings and the intensity of his faith in God, that his nearest relations, his wife, beloved cousin and intimate friends, were most thoroughly imbued with the truth of his mission and convinced of his inspiration.
Those who knew him best, closest relations and dearest friends, people who lived with him and noted all his movements, were his sincere and most devoted followers." John Davenport writes in his Apology for Mohammed and the Koran: "It is strongly corroborative of Mohammed's sincerity that the earliest converts to Islam were his bosom friends and the people of his household, who, all intimately acquainted with his private life, could not fail to have detected those discrepancies which more or less invariably exist between the pretensions of the hypocritical deceiver and his actions at home." Slowly the message spread.
During the first three years, he gained only thirty followers. In spite of the caution and care exercised, the Quraish were well posted with what was going on. At first they did not take much note and only jeered at the Prophet and the plight of his followers. They doubted his sanity and thought him crazed and possessed.