It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that when this verse was revealed, "Indeed, those who lower their voices in the presence of the Messenger of Allah" [Surah al-Hujurat: 3] , Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) said: "O Messenger of Allah, by the One who revealed the Book to you, from now on I will speak to you only as one who whispers a most confidential secret, until I meet Allah, the Mighty and Majestic." This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.