Sahih al-Bukhari 39
Sahih al-Bukhari · Book 2: Belief · Religion is very easy
Narrated Abu Huraira:
حَدَّثَنَا عَبْدُ السَّلاَمِ بْنُ مُطَهَّرٍ ، قَالَ حَدَّثَنَا عُمَرُ بْنُ عَلِيٍّ ، عَنْ مَعْنِ بْنِ مُحَمَّدٍ الْغِفَارِيِّ ، عَنْ سَعِيدِ بْنِ أَبِي سَعِيدٍ الْمَقْبُرِيِّ ، عَنْ أَبِي هُرَيْرَةَ ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " إِنَّ الدِّينَ يُسْرٌ، وَلَنْ يُشَادَّ الدِّينَ أَحَدٌ إِلاَّ غَلَبَهُ، فَسَدِّدُوا وَقَارِبُوا وَأَبْشِرُوا، وَاسْتَعِينُوا بِالْغَدْوَةِ وَالرَّوْحَةِ وَشَىْءٍ مِنَ الدُّلْجَةِ " .
The Prophet (ﷺ) said, "Religion is very easy and whoever overburdens himself in his religion will not be able to continue in that way. So you should not be extremists, but try to be near to perfection and receive the good tidings that you will be rewarded; and gain strength by worshipping in the mornings, the afternoons, and during the last hours of the nights." (See Fath-ul-Bari, Page 102, Vol 1).