"Al-Aqra' bin Habis arrived to meet the Prophet ﷺ" - he said - "so Abu Bakr said: 'O Messenger of Allah! Appoint him over his people.' 'Umar said: 'Do not appoint him O Messenger of Allah!' They continued talking before the Prophet ﷺ until they raised their voices. Abu Bakr said to 'Umar: 'You only wanted to contradict me.' So ['Umar] said: 'I did not want to contradict you.'" He said: "So this Ayah was revealed: 'O you who believe! Do not raise your voices above the voice of the Prophet (49:2).'" He said: "After that, when 'Umar spoke before the Prophet ﷺ, his speech could not be heard until he told him he could not understand him." He (one of the narrators) said: "And Ibn Az-Zubair did not mention his grandfather" meaning Abu Bakr. (Using translation from Tirmidhī 3266)
أَنَّ الْأَقْرَعَ بْنَ حَابِسٍ قَدِمَ عَلَى النَّبِيِّ ﷺ فَقَالَ أَبُو بَكْرٍ يَا رَسُولَ اللهِ اسْتَعْمِلْهُ عَلَى قَوْمِهِ فَقَالَ عُمَرُ لَا تَسْتَعْمِلْهُ يَا رَسُولَ اللهِ فَتَكَلَّمَا عِنْدَ النَّبِيِّ ﷺ حَتَّى ارْتَفَعَتْ أَصْوَاتُهُمَا فَقَالَ أَبُو بَكْرٍ لِعُمَرَ مَا أَرَدْتَ إِلَّا خِلَافِي قَالَ مَا أَرَدْتُ خِلَافَكَ قَالَ فَنَزَلَتْ {يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَرْفَعُوا أَصْوَاتَكُمْ فَوْقَ صَوْتِ النَّبِيِّ} وَكَانَ عُمَرُ بَعْدَ ذَلِكَ إِذَا تَكَلَّمَ عِنْدَ النَّبِيِّ ﷺ لَمْ يَسْمَعْ كَلَامَهُ حَتَّى يَسْتَفْهِمَهُ