Narrated Ibn Abi Mulaika: `Abdullah bin Az-Zubair said that a group of riders belonging to Banu Tamim came to the Prophet, Abu Bakr said (to the Prophet), "Appoint Al-Qa'qa bin Mabad bin Zurara as (their) ruler." `Umar said (to the Prophet). "No! But appoint Al-Aqra bin H`Abis." Thereupon Abu Bakr said (to `Umar). "You just wanted to oppose me." `Umar replied. "I did not want to oppose you." So both of them argued so much that their voices became louder, and then the following Divine Verses were revealed in that connection:-- "O you who believe! Do not be forward in the presence of Allah and His Apostle..." (till the end of Verse)...(49.1)