كتاب الإيمان
1  
The Book of Faith
(4)
Chapter: Explaining the faith by means of which a person is admitted into paradise, and that the one who adheres to what is enjoined upon him will enter paradise
(4)
باب بَيَانِ الإِيمَانِ الَّذِي يُدْخَلُ بِهِ الْجَنَّةُ وَأَنَّ مَنْ تَمَسَّكَ بِمَا أُمِرَ بِهِ دَخَلَ الجَنَّةَ
Sahih Muslim 14 b

It is reported on the authority of Abu Huraira that a bedouin came to the Messenger of Allah (ﷺ) and said:

Messenger of Allah, direct me to a deed by which I may be entitled to enter Paradise. Upon this he (the Holy Prophet) remarked: You worship Allah and never associate anything with Him, establish the obligatory prayer, and pay the Zakat which is incumbent upon you, and observe the fast of Ramadan. He (the bedouin) said: By Him in Whose hand is my life, I will never add anything to it, nor will I diminish anything from it. When he (the bedouin) turned his back, the Prophet (ﷺ) said: He who is pleased to see a man from the dwellers of Paradise should catch a glimpse of him.
وَحَدَّثَنِي أَبُو بَكْرِ بْنُ إِسْحَاقَ، حَدَّثَنَا عَفَّانُ، حَدَّثَنَا وُهَيْبٌ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ أَبِي زُرْعَةَ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ أَعْرَابِيًّا، جَاءَ إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ دُلَّنِي عَلَى عَمَلٍ إِذَا عَمِلْتُهُ دَخَلْتُ الْجَنَّةَ ‏.‏ قَالَ ‏"‏ تَعْبُدُ اللَّهَ لاَ تُشْرِكُ بِهِ شَيْئًا وَتُقِيمُ الصَّلاَةَ الْمَكْتُوبَةَ وَتُؤَدِّي الزَّكَاةَ الْمَفْرُوضَةَ وَتَصُومُ رَمَضَانَ ‏"‏ ‏.‏ قَالَ وَالَّذِي نَفْسِي بِيَدِهِ لاَ أَزِيدُ عَلَى هَذَا شَيْئًا أَبَدًا وَلاَ أَنْقُصُ مِنْهُ ‏.‏ فَلَمَّا وَلَّى قَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ مَنْ سَرَّهُ أَنْ يَنْظُرَ إِلَى رَجُلٍ مِنْ أَهْلِ الْجَنَّةِ فَلْيَنْظُرْ إِلَى هَذَا ‏"‏ ‏.‏
Reference : Sahih Muslim 14b
In-book reference : Book 1, Hadith 15
USC-MSA web (English) reference : Book 1, Hadith 14
  (deprecated numbering scheme)