Khabbab used to visit his brothers who hid their Islam in dread to the Quraish tyranny. There he used to read the Qur'an and instruct them. He was truly a genius in studying every surah and verse in the Qur'an.
Khabbab was the one teaching Qur'an to Fatimah bint Al khataab and her husband Sa'iid ibn Zaid, when Umar ibn Al khataab thrust his way inside the house with a sword so as to settle his account with Islam and the prophet (s.a.w).
Allah willed that as soon as Umar heard the verse in the scroll being recited pleasantly by khabbab's voice , he cried out,"TELL ME WHERE MUHAMMAD IS!!!". When khabbab heard Umar's voice he came out of his hiding place and said,"Umar , by Allah! I hope that Allah chooses you to fulfill the prophets supplication. For yesterday, I heard the prophet say, 'Allah, please support Islam with whom you love best, either Abi Al-Hakam Ibn Hishaam or Umar ibn Al-Khataab".
Umar repeated his question "WHERE IS MUHAMMAD NOW?!!" Khabbab answered "At As-Safaa in Dar Al-Arqam ibn Abi Arqam". At that moment , Umar ascended towards his great fortune and blessed destiny.