Ibn ‘Umar (Radia-Allaahu ‘anhuma) narrated that Allaah’s Messenger (Salla-Allaahu ‘alayhi wa sallam) said:
“You should observe part of the [Nafl (voluntary)] Salaat (prayer) in your homes. Do not turn your homes into graves.”
[Al- Bukhaari and Muslim]
Commentary: “You should observe part of the Salaat (prayer) in your homes” here means Nafl and Sunnah.
The houses in which Nafl are not offered are like graveyards.
Such houses are like graves which have no scope for action and worship and are thus deprived of their reward, which is a great deprivation indeed.