" There was no question of ‘Umar’s keeping his Islam secret. He wished to tell everyone, in particular those who were most hostile to the Prophet. In after years he used to say “When I entered Islam that night, I thought to myself: Which of the people in Mecca is the most violent in enmity against God’s Messenger, that I may go to him and tell him I have become a Muslim? My answer was: Abu Jahl. So the next morning I went and knocked at his door, and Abu Jahl came out and said: “The best of welcomes to my sister’s son! What hath brought thee here?” I answered: “I came to tell thee that I believe in God and in His Messenger Muhammad; and I testify to the truth of that which he hath brought.” “God curse thee!” he said, “and may His curse be on the tidings thou hast brought!” Then he slammed the door in my face. "

― , Muhammad: His Life Based on the Earliest Sources