During this period, 'Umar Ibn Al-Khattab adopted Islam. In him the new faith gained a valuable adherent and an important factor in the future development and propagation of Islam.
Hitherto he had been a violent opposer of the Prophet and a bitter enemy of Islam. His conversion is said to have been worked by the miraculous effect on his mind of a surah of the Qur'an which his sister was reading in her house, where he had gone with the intention of killing her for adopting Islam. Thus the party of the Prophet had been strengthened by the conversion of his uncle Hamza, a man of great valor and merit; and of Abu Bakr and Umar, both men of great energy and reputation. The Muslims now ventured to perform their devotions in public.
Related Quran Ayaaths of this Hadith.
Surah 3 : Ayah 144 Surah 2 : Ayah 4 Surah 2 : Ayah 23 Surah 2 : Ayah 80 Surah 2 : Ayah 90 Surah 2 : Ayah 93 Surah 2 : Ayah 94 Surah 2 : Ayah 97 Surah 2 : Ayah 105 Surah 2 : Ayah 108 Surah 5 : Ayah 17 Surah 5 : Ayah 48 Surah 5 : Ayah 49 Surah 3 : Ayah 12 Surah 3 : Ayah 20 Surah 3 : Ayah 31 Surah 6 : Ayah 10 Surah 6 : Ayah 11 Surah 4 : Ayah 41"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari