Umar
Conversion to Islam and service under Muhammad

Umar converted to Islam in 616, one year after the Migration to Abyssinia.The story was recounted in Ibn Ishaq 's Sīrah. On his way to murder Muhammad, Umar met his best friend Nu'aym ibn Abd Allah who had secretly converted to Islam but had not told Umar. When Umar informed him that he had set out to kill Muhammad, Nu'aym said, “By God, you have deceived yourself, O Umar! Do you think that Banu Abd al-Manaf would let you run around alive once you had killed their son Muhammad? Why don't you return to your own house and at least set it straight?"

Nuaimal Hakim told him to inquire about his own house where his sister and her husband had converted to Islam. Upon arriving at her house, Umar found his sister and brother-in-law Saeed bin Zaid (Umar's cousin) reciting the verses of the Quran from sura Ta-Ha. He started quarreling with his brother-in-law. When his sister came to rescue her husband, he also started quarreling with her. Yet still they kept on saying "you may kill us but we will not give up Islam". Upon hearing these words, Umar slapped his sister so hard that she fell to the ground bleeding from her mouth. When he saw what he did to his sister, he calmed down out of guilt and asked his sister to give him what she was reciting. His sister replied in the negative and said "You are unclean, and no unclean person can touch the Scripture." He insisted, but his sister was not prepared to allow him to touch the pages unless he washed his body. Umar at last gave in. He washed his body and then began to read the verses that were: Verily, I am Allah: there is no God but Me; so serve Me (only), and establish regular prayer for My remembrance (Quran 20:14). He wept and declared, "Surely this is the word of Allah. I bear witness that Muhammad is the Messenger of Allah." On hearing this, Khabbab came out from inside and said: "O, Umar! Glad tidings for you. Yesterday Muhammad prayed to Allah, 'O, Allah! Strengthen Islam with either Umar or Abu Jahl, whomsoever Thou likest.' It seems that his prayer has been answered in your favour."

Umar then went to Muhammad with the same sword he intended to kill him with and accepted Islam in front of him and his companions. Umar was 39 years old when he accepted Islam.

According to one account, after his conversion to Islam Umar openly prayed at the Kaaba as the Quraish chiefs, Abu Jahl and Abu Sufyan, reportedly watched in anger. This further helped the Muslims to gain confidence in practicing Islam openly. At this stage Umar even challenged anyone who dared to stop the Muslims from praying, although no one dared to interfere with Umar when he was openly praying.

Umar's conversion to Islam granted power to the Muslims and to the Islamic faith in Mecca. It was after this event that Muslims offered prayers openly in Masjid al-Haram for the first time. Abdullah ibn Masud said,

Umar's embracing Islam was our victory, his migration to Medina was our success, and his reign a blessing from Allah. We didn't offer prayers in al-Haram Mosque until Umar had accepted Islam. When he accepted Islam, the Quraysh were compelled to let us pray in the Mosque.
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