Narrated Abu Hurairah [radhi-yAllâhu 'anhu]:
The Prophet [sal-Allâhu 'alayhi wa sallam] said,
"No Salât (prayer) is more heavy (harder) for the hypocrites than the Fajr
and the 'Ishâ prayer; but if they knew the reward for these Salât (prayers)
at their respective times, they would certainly present themselves
(in the mosques) even if they had to crawl."
(Bukhari, Muslim)