Volume 6, Book 60, Number 370:
Narrated Abdullah bin Az-Zubair:
A group of Bani Tamim came to the Prophet (and requested him to appoint a governor for them).
Abu Bakr said, “Appoint Al-Qaqa bin Mabad.” Umar said, “Appoint Al-Aqra’ bin Habeas.” On that
Abu Bakr said (to ‘Umar). “You did not want but to oppose me!” ‘Umar replied “I did not intend to op –
pose you!” So both of them argued till their voices grew loud. So the following Verse was revealed:
‘O you who believe! Be not for ward……’ (49.1)