O Ye who believe! Put not yourselves forward before Allah and His Messenger; but fear Allah: for Allah is He Who hears and knows all things. O ye who believe! Raise not your voices above the voice of the Prophet, nor speak aloud to him in talk, as ye may speak aloud to one another, lest your deeds become vain and ye perceive not. Those that lower their voices in the presence of Allah's Messenger,- their hearts has Allah tested for piety: for them is Forgiveness and a great Reward.
• Sahih Bukhari, Volume 6, Book 60, #368, Book: al-Tafseer; Page 1052, #4845
• Sahih Bukhari, Volume 9, Book 92, #405, Book: Holding Fast to The Quran and The Sunnah; Page 1534, #7302
• Sahih Bukhari, Volume 6, Book 60, #370, Book: al-Tafseer; Page 1053, #4847
• Sahih Bukhari, Volume 5, Book 59, #653, Book: al-Maghaazi; Page 908, #4367
And never offer prayer for any one of them who dies and do not stand by his grave; surely they disbelieve in Allah and His Messenger and they shall die in transgression.