Umar ibn al-Khattab became a Muslim, three days after Hamza became Muslim.
One day, Umar radiallahu anhu said, "O Messenger of Allah, are we not on the right path?". He (the Holy Prophet) said: ''We are on the right way''. ''Then why do we hide ourselves?'' Umar said.
On that day, Muslims for the first time went straight to the Sacred House openly. One rank was led by Hamza and the other by Umar. They entered the Sacred Mosque (Baytullah). The Quraysh turned to Hamzah then Umar and were afraid deeply.
That day, the Messenger of Allah peace and blessings of Allaah be upon him gave Umar ibn al-Khattab the nickname of "Faruq" that means to distinguish between right and wrong.