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 Habis." 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)

حَدَّثَنِي إِبْرَاهِيمُ بْنُ مُوسَى، حَدَّثَنَا هِشَامُ بْنُ يُوسُفَ، أَنَّ ابْنَ جُرَيْجٍ، أَخْبَرَهُمْ عَنِ ابْنِ أَبِي مُلَيْكَةَ، أَنَّ عَبْدَ اللَّهِ بْنَ الزُّبَيْرِ، أَخْبَرَهُمْ أَنَّهُ، قَدِمَ رَكْبٌ مِنْ بَنِي تَمِيمٍ عَلَى النَّبِيِّ ﷺ فَقَالَ أَبُو بَكْرٍ أَمِّرِ الْقَعْقَاعَ بْنَ مَعْبَدِ بْنِ زُرَارَةَ. قَالَ عُمَرُ بَلْ أَمِّرِ الأَقْرَعَ بْنَ حَابِسٍ. قَالَ أَبُو بَكْرٍ مَا أَرَدْتَ إِلاَّ خِلاَفِي. قَالَ عُمَرُ مَا أَرَدْتُ خِلاَفَكَ. فَتَمَارَيَا حَتَّى ارْتَفَعَتْ أَصْوَاتُهُمَا فَنَزَلَ فِي ذَلِكَ {يَا أَيُّهَا الَّذِينَ آمَنُوا لاَ تُقَدِّمُوا} حَتَّى انْقَضَتْ.