In this Ayah, Allah made it obligatory for the Muslims to fight in Jihad against the evil of the enemy who transgress against Islam. Az-Zuhri said, "Jihad is required from every person, whether he actually joins the fighting or remains behind. Whoever remains behind is required to give support, if support is warranted; to provide aid, if aid is needed; and to march forth, if he is commanded to do so. If he is not needed, then he remains behind.'' It is reported in the Sahih:
« مَنْ مَاتَ وَلَمْ يَغْزُ وَلَمْ يُحَدِّثْ نَفْسَهُ بِالْغَزْوِ، مَاتَ مِيتَةً جَاهِلِيَّة »
(Whoever dies but neither fought (i.e., in Allah's cause), nor sincerely considered fighting, will die a death of Jahiliyyah (pre-Islamic era of ignorance).)
On the day of Al-Fath (when he conquered Makkah), the Prophet said:
« لَا هِجْرَةَ بَعْدَ الْفَتْحِ وَلكِنْ جِهَادٌ وَنِيَّةٌ، وَإِذَا اسْتُنْفِرْتُمْ فَانْفِرُوا »
(There is no Hijrah (migration from Makkah to Al-Madinah) after the victory, but only Jihad and good intention. If you were required to march forth, then march forth.)
﴿ وَهُوَ كُرۡهٌ۬ لَّكُمۡۖ ﴾
(...though you dislike it) means, `Fighting is difficult and heavy on your hearts.' Indeed, fighting is as the Ayah describes it, as it includes being killed, wounded, striving against the enemies and enduring the hardship of travel. Allah then said:
﴿ وَعَسَىٰٓ أَن تَكۡرَهُواْ شَيۡـًٔ۬ا وَهُوَ خَيۡرٌ۬ لَّڪُمۡۖ ﴾
(. ..and it may be that you dislike a thing which is good for you) meaning, fighting is followed by victory, dominance over the enemy, taking over their lands, money and offspring. Allah continues:
﴿ وَعَسَىٰٓ أَن تُحِبُّواْ شَيۡـًٔ۬ا وَهُوَ شَرٌّ۬ لَّكُمۡۗ ﴾
(...and that you like a thing which is bad for you.)
This Ayah is general in meaning. Hence, one might covet something, yet in reality it is not good or beneficial for him, such as refraining from joining the Jihad, for it might lead to the enemy taking over the land and the government. Then, Allah said:
﴿ وَٱللَّهُ يَعۡلَمُ وَأَنتُمۡ لَا تَعۡلَمُونَ ﴾
(Allah knows, but you do not know.) meaning, He has better knowledge than you of how things will turn out to be in the end, and of what benefits you in this earthly life and the Hereafter. Hence, obey Him and adhere to His commands, so that you may acquire the true guidance.
﴿ يَسۡـَٔلُونَكَ عَنِ ٱلشَّہۡرِ ٱلۡحَرَامِ قِتَالٍ۬ فِيهِۖ قُلۡ قِتَالٌ۬ فِيهِ كَبِيرٌ۬ۖ وَصَدٌّ عَن سَبِيلِ ٱللَّهِ وَڪُفۡرُۢ بِهِۦ وَٱلۡمَسۡجِدِ ٱلۡحَرَامِ وَإِخۡرَاجُ أَهۡلِهِۦ مِنۡهُ أَكۡبَرُ عِندَ ٱللَّهِۚ وَٱلۡفِتۡنَةُ أَڪۡبَرُ مِنَ ٱلۡقَتۡلِۗ وَلَا يَزَالُونَ يُقَـٰتِلُونَكُمۡ حَتَّىٰ يَرُدُّوكُمۡ عَن دِينِڪُمۡ إِنِ ٱسۡتَطَـٰعُواْۚ وَمَن يَرۡتَدِدۡ مِنكُمۡ عَن دِينِهِۦ فَيَمُتۡ وَهُوَ ڪَافِرٌ۬ فَأُوْلَـٰٓٮِٕكَ حَبِطَتۡ أَعۡمَـٰلُهُمۡ فِى ٱلدُّنۡيَا وَٱلۡأَخِرَةِۖ وَأُوْلَـٰٓٮِٕكَ أَصۡحَـٰبُ ٱلنَّارِۖ هُمۡ فِيهَا خَـٰلِدُونَ • إِنَّ ٱلَّذِينَ ءَامَنُواْ وَٱلَّذِينَ هَاجَرُواْ وَجَـٰهَدُواْ فِى سَبِيلِ ٱللَّهِ أُوْلَـٰٓٮِٕكَ يَرۡجُونَ رَحۡمَتَ ٱللَّهِۚ وَٱللَّهُ غَفُورٌ۬ رَّحِيمٌ۬ ﴾
(217. They ask you concerning fighting in the Sacred Months. Say, "Fighting therein is a great (transgression) but a greater (transgression) with Allah is to prevent mankind from following the way of Allah, to disbelieve in Him, to prevent access to Al-Masjid Al-Haram (at Makkah), and to drive out its inhabitants, and Al-Fitnah is worse than killing.'' And they will never cease fighting you until they turn you back from your religion (Islamic Monotheism) if they can. And whosoever of you turns back from his religion and dies as a disbeliever, then his deeds will be lost in this life and in the Hereafter, and they will be the dwellers of the Fire. They will abide therein forever.) (218. Verily, those who have believed, and those who have emigrated (for Allah's religion) and have striven hard in the way of Allah, all these hope for Allah's mercy. And Allah is Oft-Forgiving, Most-Merciful.)