In an address to the believers of this Ummah, Allah ordered them to fast, that is, to abstain from food, drink and sexual activity with the intention of doing so sincerely for Allah the Exalted alone. This is because fasting purifies the souls and cleanses them from the evil that might mix with them and their ill behavior. Allah mentioned that He has ordained fasting for Muslims just as He ordained it for those before them, they being an example for them in that, so they should vigorously perform this obligation more obediently than the previous nations. Similarly, Allah said:

﴿لِكُلٍّ جَعَلْنَا مِنكُمْ شِرْعَةً وَمِنْهَـجاً وَلَوْ شَآءَ اللَّهُ لَجَعَلَكُمْ أُمَّةً وَحِدَةً وَلَـكِن لِّيَبْلُوَكُمْ فِى مَآ ءَاتَـكُم فَاسْتَبِقُوا الخَيْرَاتِ﴾

(To each among you, We have prescribed a law and a clear way. If Allah had willed, He would have made you one nation, but that (He) may test you in what He has given you; so compete in good deeds.) (5:48)

Allah said in this Ayah:

﴿يأَيُّهَا الَّذِينَ ءَامَنُواْ كُتِبَ عَلَيْكُمُ الصِّيَامُ كَمَا كُتِبَ عَلَى الَّذِينَ مِن قَبْلِكُمْ لَعَلَّكُمْ تَتَّقُونَ ﴾

(O you who believe! Fasting is prescribed for you as it was prescribed for those before you, that you may have Taqwa).) since the fast cleanses the body and narrows the paths of Shaytan. In the Sahihayn the following Hadith was recorded:

«يَا مَعْشَرَ الشَّبَابِ مَنِ اسْتَطَاعَ مِنْكُمُ الْبَاءَةَ فَلْيتَـزَوَّجْ وَمَنْ لَمْ يَسْتَطِع فَعَلَيْهِ بِالصَّوْمِ فَإِنَّهُ لَهُ وِجَاء»

.(O young people! Whoever amongst you can afford marriage, let him marry. Whoever cannot afford it, let him fast, for it will be a shield for him.)

Allah then states that the fast occurs during a fixed number of days, so that it does not become hard on the hearts, thereby weakening their resolve and endurance.)