It was narrated from Abu Hurayrah that the Prophet (peace and blessings of Allaah be upon him) said: “The first thing among their deeds for which the people will be brought to account on the Day of Resurrection will be prayer. Our Lord will say to His angels, although He knows best, ‘Look at My slave’s prayer, is it complete or lacking?’ If it is complete, it will be recorded as complete, but if it is lacking, He will say, ‘Look and see whether my slave did any voluntary (naafil) prayers.’ If he had done voluntary prayers, He will say, ‘Complete the obligatory prayers of My slave from his voluntary prayers.’ Then the rest of his deeds will be examined in a similar manner.”
(Narrated by Abu Dawood, 864; classed as saheeh by al-Albaani in Saheeh Abi Dawood, 770).
Hadith by the Prophet (May peace and blessings be upon him) in which he said:
“Allaah will build a house in Heaven for whoever is diligent in observing 12 Sunnah Rak’aat (as follows): 4 Rak’aat before and 2 after the Dhuhr (Midday) Prayer, 2 after the Maghrib (Sunset Prayer), 2 after the Ishaa (Evening) Prayer and 2 before the Fajr (Dawn) Prayer.” Hadith sahih narrated by at-Tirmidhi No. 379 and by others. Hadith No. 6183 in Sahih al-Jaami.