صحيح البخاري

Narrated Ibn Abi Mulaika:

Once the two righteous men, i.e., Abu Bakr and `Umar were on the verge of destruction (and that was because): When the delegate of Bani Tamim came to the Prophet, one of them (either Abu Bakr or `Umar) recommended Al-Aqra' bin H`Abis at-Tamimi Al-Hanzali, the brother of Bani Majashi (to be appointed as their chief), while the other recommended somebody else. Abu Bakr said to `Umar, "You intended only to oppose me." `Umar said, "I did not intend to oppose you!" Then their voices grew louder in front of the Prophet (ﷺ) whereupon there was revealed: 'O you who believe! Do not raise your voices above the voice of the Prophet..a great reward.' (49.2-3) Ibn Az-Zubair said, 'Thence forward when `Umar talked to the Prophet, he would talk like one who whispered a secret and would even fail to make the Prophet (ﷺ) hear him, in which case the Prophet (ﷺ) would ask him (to repeat his words).