It is narrated from Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) that a delegation of Banu Tamim came to the Prophet (peace and blessings be upon him), among whom was al-Aqra' bin Habis. Sayyiduna Abu Bakr (may Allah be pleased with him) said: O Messenger of Allah, appoint al-Aqra' as governor over his people. Sayyiduna Umar (may Allah be pleased with him) said: O Messenger of Allah, do not appoint him as governor. The two of them argued until their voices were raised, so concerning that this verse was revealed: "O you who believe, do not put yourselves forward before Allah and His Messenger" [Surah al-Hujurat: 1], until the verse was completed.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13873