Allah, the Majestic and the Exalted, said: Every act of the son of Adam is for him except fasting. It is done for My sake, and I will give a reward for it. By Allah in Whose Hand is the life of Muhammad, the breath of the observer of fast is sweeter to Allah than the fragrance of musk.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ قَالَ اللَّهُ ﷻ كُلُّ عَمَلِ ابْنِ آدَمَ لَهُ إِلاَّ الصِّيَامَ هُوَ لِي وَأَنَا أَجْزِي بِهِ فَوَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخِلْفَةُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ  

Fasting is a shield.  

قَالَ رَسُولُ اللَّهِ ﷺ الصِّيَامُ جُنَّةٌ  

Allah the Exalted and Majestic said: Every act of the son of Adam is for him, except fasting. It is (exclusively) meant for Me and I (alone) will reward it. Fasting is a shield. When any one of you is fasting on a day, he should neither indulge in obscene language, nor raise the voice; or if anyone reviles him or tries to quarrel with him he should say: I am a person fasting. By Him, in Whose Hand is the life of Muhammad, the breath of the observer of fast is sweeter to Allah on the Day of judgment than the fragrance of musk. The one who fasts has two (occasions) of joy, one when he breaks the fast he is glad with the breaking of (the fast) and one when he meets his Lord he is glad with his fast.  

أَنَّهُ سَمِعَ أَبَا هُرَيْرَةَ ؓ يَقُولُ قَالَ رَسُولُ اللَّهِ ﷺ قَالَ اللَّهُ ﷻ كُلُّ عَمَلِ ابْنِ آدَمَ لَهُ إِلاَّ الصِّيَامَ فَإِنَّهُ لِي وَأَنَا أَجْزِي بِهِ وَالصِّيَامُ جُنَّةٌ فَإِذَا كَانَ يَوْمُ صَوْمِ أَحَدِكُمْ فَلاَ يَرْفُثْ يَوْمَئِذٍ وَلاَ يَسْخَبْ فَإِنْ سَابَّهُ أَحَدٌ أَوْ قَاتَلَهُ فَلْيَقُلْ إِنِّي امْرُؤٌ صَائِمٌ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ يَوْمَ الْقِيَامَةِ مِنْ رِيحِ الْمِسْكِ وَلِلصَّائِمِ فَرْحَتَانِ يَفْرَحُهُمَا إِذَا أَفْطَرَ فَرِحَ بِفِطْرِهِ وَإِذَا لَقِيَ رَبَّهُ فَرِحَ بِصَوْمِهِ  

Every (good) deed of the son of Adam would be multiplied, a good deed receiving a tenfold to seven hundredfold reward. Allah, the Exalted and Majestic, has said: With the exception of fasting, for it is done for Me and I will give a reward for it, for one abandons his passion and food for My sake.

There are two occasions of joy for one who fasts, joy when he breaks it, and joy when he meets his Lord, and the breath (of an observer of fast) is sweeter to Allah than the fragrance of musk.  

قَالَ رَسُولُ اللَّهِ ﷺ: «كُلُّ عَمَلِ ابْنِ آدَمَ يُضَاعَفُ الْحَسَنَةُ عَشْرُ أَمْثَالِهَا إِلَى سَبْعِمِائَةِ ضِعْفٍ۔ قَالَ اللَّهُ ﷻ: إِلاَّ الصَّوْمَ: فَإِنَّهُ لِي وَأَنَا أَجْزِي بِهِ: يَدَعُ شَهْوَتَهُ، وَطَعَامَهُ مِنْ أَجْلِي۔»

«لِلصَّائِمِ فَرْحَتَانِ فَرْحَةٌ عِنْدَ فِطْرِهِ وَفَرْحَةٌ عِنْدَ لِقَاءِ رَبِّهِ؛ وَلَخُلُوفُ فِيهِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ۔»  

Allah, the Exalted and Majestic, said: Fast (is exclusively) meant for Me and I would give its reward. There are two (occasions) of joy for the observer of fast. He feels joy when he breaks the fast and he is happy when he meets Allah. By Allah in Whose Hand is the life of Muhammad, the breath of the observer of fast is sweeter to Allah than the fragrance of musk.  

عَنْ أَبِي هُرَيْرَةَ وَأَبِي سَعِيدٍ ؓ قَالاَ قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ اللَّهَ ﷻ يَقُولُ إِنَّ الصَّوْمَ لِي وَأَنَا أَجْزِي بِهِ إِنَّ لِلصَّائِمِ فَرْحَتَيْنِ إِذَا أَفْطَرَ فَرِحَ وَإِذَا لَقِيَ اللَّهَ فَرِحَ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَخُلُوفُ فَمِ الصَّائِمِ أَطْيَبُ عِنْدَ اللَّهِ مِنْ رِيحِ الْمِسْكِ  

" As he meets Allah, He rewards him, and he is happy."  

وَقَالَ إِذَا لَقِيَ اللَّهَ فَجَزَاهُ فَرِحَ  

In Paradise there is a gate which is called Rayyan through which only the people who fast would enter on the Day on Resurrection. None else would enter along with them. It would be proclaimed: Where are the people who fast that they should be admitted into it? And when the last of them would enter, it would be closed and no one would enter it.  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّ فِي الْجَنَّةِ بَابًا يُقَالُ لَهُ الرَّيَّانُ يَدْخُلُ مِنْهُ الصَّائِمُونَ يَوْمَ الْقِيَامَةِ لاَ يَدْخُلُ مَعَهُمْ أَحَدٌ غَيْرُهُمْ يُقَالُ أَيْنَ الصَّائِمُونَ فَيَدْخُلُونَ مِنْهُ فَإِذَا دَخَلَ آخِرُهُمْ أُغْلِقَ فَلَمْ يَدْخُلْ مِنْهُ أَحَدٌ