4. So, when you meet those who disbelieve (in battle), smite (their) necks until you have fully defeated them, then tighten their bonds. Thereafter (is the time) either for generosity or ransom, until the war lays down its burden. Thus, and had Allah so willed, He could have taken vengeance against them;--but (He lets you struggle) so as to test with one another. But those who are killed in the way of Allah, He will never let their deeds be lost. 5. He will guide them and amend their condition. 6. And admit them to Paradise, which He has made known to them. 7. O you who believe! If you support (in the cause of) Allah, He will support you, and make your foothold firm. 8. But as for those who disbelieve, misery awaits them, and (Allah) will make their deeds vain. 9. That is because they hate that which Allah has sent down; so He has made their deeds fruitless.
Guiding the believers to what they should employ in their fights against the idolators, Allah says,
(So, when you meet those who disbelieve (in battle), smite their necks) which means, `when you fight against them, cut them down totally with your swords.'
(until you have fully defeated them,) meaning, `you have killed and utterly destroyed them.'
(tighten their bonds.) `This is referring to the prisoners of war whom you have captured. Later on, after the war ends and the conflict has ceased, you have a choice in regard to the captives: You may either act graciously toward them by setting them free without charge, or free them for a ransom that you require from them.' It appears that this Ayah was revealed after the battle of Badr. At that time, Allah reproached the believers for sparing many of the enemy's soldiers, and holding too many captives in order to take ransom from them. So He said then:
(It is not for a Prophet to have captives of war until he had made a great slaughter (among the enemies) in the land. You desire the commodities of this world, but Allah desires (for you) the Hereafter. Allah is Mighty and Wise. Were it not for a prior decree from Allah, a severe torment would have touched you for what you took.) (8:67-68) Allah's saying,
(...until the war lays down its burden.) Mujahid said: "Until `Isa bin Maryam (peace be upon him) descends.'' It seems as if he derived this opinion from the Prophet's saying,
(There will always be a group of my Ummah victorious upon the truth, until the last of them fight against Ad-Dajjal.) Imam Ahmad recorded from Jubayr bin Nufayr who reported from Salamah bin Nufayl that he went to the Messenger of Allah and said, "I have let my horse go, and thrown down my weapon, for the war has ended. There is no more fighting.'' Then the Prophet said to him,
(Now the time of fighting has come. There will always be a group of my Ummah dominant over others. Allah will turn the hearts of some people away (from the truth), so they (that group) will fight against them, and Allah will bestow on them (war spoils) from them (the enemies) -- until Allah's command comes to pass while they are in that state. Verily, the center of the believers' abode is Ash-Sham. And goodness is tied around the horses' foreheads till the Day of Resurrection.) An-Nasa'i also recorded this narration. Allah then says,
(Thus, and had Allah so willed, He could have taken vengeance against them;) which means that had He so willed, He could have taken immediate vengeance against the disbelievers with a chastisement or exemplary punishment directly from Him.
(but (He lets you struggle) so as to test with one another.) meaning, He has ordered Jihad and fighting against the enemies in order to try you and test your affairs. Allah also expresses His wisdom by the legislation of Jihad in the following two Surahs, Al `Iman and At-Tawbah, in which He says,
(Or did you think that you would enter the Paradise before Allah had made evident those of you who fight in His cause and made evident those who are steadfast) (3:142)
(Fight them; Allah will then punish them by your hands, disgrace them, grant you victory over them, satisfy the breasts of a believing people, and remove the fury of their (the believers') hearts. Allah turns in forgiveness to whom He wills; Allah is Knowing and Wise.) ( 9:14-15)
Since it is customary during wars that many of the believers die, Allah says:
(But those who are killed in the way of Allah, He will never let their deeds be lost.) which means that He would not let their good deeds go to waste, but would rather multiply and increase them. Some of them will continue being rewarded for their good deeds for the entire length of their stay in Al-Barzakh. This has been mentioned in a Hadith recorded by Imam Ahmad in his Musnad on the authority of Kathir bin Murrah, who reported from Qays Al-Judhami, may Allah be pleased with him, that Allah's Messenger said,
(As the first drop of his blood gushes forth, a martyr is granted six merits: all of his sins are forgiven, he is shown his place in Paradise, he is married to wide-eyed Huris, he is secured from the great fear (on Judgement Day) and the torment of the grave, and he is adorned with the adornments of Iman.) Ahmad was alone in recording this Hadith. Abu Ad-Darda', may Allah be pleased with him, reported that Allah's Messenger said,
(A martyr is allowed to intercede for seventy members of his household. ) This was recorded by Abu Dawud, and there are numerous other Hadiths mentioning the merits of the martyrs. As for Allah's saying,
(He will guide them) meaning, He will guide them to Jannah. This is similar to Allah's saying,
(Indeed, those who have believed and done righteous good deeds, their Lord will guide them because of their Faith: beneath them rivers will flow in the Gardens of Pleasure.) (10:9) Allah says,
(and amend their condition.) meaning, their situation and affairs.
(And (He will) admit them to Paradise, which He has made known to them.) It means that He has acquainted them with Paradise and guided them to it. Mujahid said: "The people of Paradise will be guided to their houses and dwellings and whatever sections Allah has ordained for them in it. They will not make mistakes in this, nor will they ask anyone for directions to their dwellings -- as if they had dwelt in it from the time they were first created.'' Al-Bukhari recorded from Abu Sa`id Al-Khudri, may Allah be pleased with him, that Allah's Messenger said,
(After the believers securely pass the Fire (on the Day of Judgement), they will be held back upon a bridge between Paradise and the Fire. There, they will have any acts of injustice that they committed against one another in the life of this world rectified. After they are completely purified and cleansed (from injustice), they will be admitted into Paradise. By the One in Whose Hand is my soul, each one of them will find his way to his dwelling in Paradise better than he found his way to his dwelling in the worldly life.)
Allah then says:
(O you who believe! If you support (the cause of) Allah, He will support you and make your foothold firm.) This is similar to His saying,
(Indeed, Allah will surely support those who support Him (His cause).) (22:40) That is because the reward is comparable to the type of deed that is performed. Thus, Allah says here,
(and make your foothold firm.) Allah then says,
(But as for those who disbelieve -- misery awaits them) This misery is the opposite of making firm the footholds of the believers who support the cause of Allah and His Messenger . It has been confirmed in a Hadith that Allah's Messenger said,
(Misery awaits the servant of the Dinar; misery awaits the servant of the Dirham; misery awaits the servant of velvet. Misery awaits him, and degeneracy; and if he is pricked by a thorn, may he not find anyone to pull it for him.) This means may Allah not cure him. Then Allah says,
(and (Allah) will make their deeds vain.) meaning, He will nullify them and make them fruitless. Thus, Allah says,
(That is because they hate that which Allah has sent down;) which means that they did not want or like what Allah revealed.
(so He made their deeds fruitless.)