Messenger of Allah (Sallallaahu ‘alaihi wasallam) said:
“He who The observes Al-Bardan (i.e., Fajr and `Asr prayers) will enter Jannah.”
[Al-Bukhari and Muslim]
It is a must for every Muslim to offer every Salat regularly but there are some prayers (Salat) which cannot be performed punctually unless one takes special care of them. This is the reason some additional merits have been mentioned in this Hadith so that people exercise extra effort for performing them. Of these two is the Fajr prayer, the performance of which is more difficult than the other prayers because it occurs at a time of rest and deep sleep. Similar is the case of `Asr prayer, the performance of which is difficult. Due to these reasons, special merits of these two prayers have been mentioned in this Hadith.
Riyad-us-Saliheen – Hadith No.1047