Abu Musa Radiyallahu 'anhu narrates that Rasullullah Sallallahu 'alaihi wasallam said: Indeed I recognise the voices of the companions belonging to the tribe of 'Ash'ari', when they enter their houses and recite Qur'an at night. I recognize their houses from their recitation of the Qur'an at night; although I may not have seen them entering their houses during daytime. (Muslim: 6407)