So, when you meet [in the battlefield] those who disbelieve, strike off their heads. Then when you have shed their blood fully, bind them [as captives]. Thereafter, free them as a favour or free them with ransom till war lays down its weapons. (47:4)

    It is evident from the words of this verse that until its revelation wars with the disbelievers had not begun, though circumstances had reached the extent that they could begin anytime. Muslims are told that if they encounter the disbelievers of Arabia, who had rejected the truth in spite of being convinced about it, in the battle field they must slay them. They deserve no lenience after such a blatant denial of the truth which had been unveiled to them by the Prophet (sws) in its ultimate form. Muslims must rout their power when they meet them in the battlefield and capture those who survive. They should know that the help of the Almighty is with them and the enemy would not be able to harm them. It is now up to them to either set free the captives as a favour to them or set them free after accepting some ransom. This is the attitude they should adopt until warfare with the disbelievers ends in Arabia.⁴³
    Although this directive is stated in the surah with reference to the Mushrikun, nothing in it restricts its application to them only. Therefore, it will apply to other combatants – whether of those times or of later – as well.
    The words that have been used to state this directive read as:  (fa imma mannan ba‘du wa imma fida’an: thereafter free them as a favour or free with them with ransom). Those who have a flare for the language know that if the word  (fida’an) here means to set free a captive after accepting ransom, then since the word (mannan) is placed in contrast to it,  (mannan) should convey the opposite meaning: that is to set them free without accepting any ransom as a favour. The word  (mannan) here is a verbal noun of a suppressed verb and since it does not occur in contrast to  (qatl: murder) and in contrast to  (fida’an), it can only and only mean the setting free of captives without accepting any ransom money. It is evident from this verse that Muslims had to set them free at all costs whether with ransom or without, and as per the Qur’an could even benefit from them in their capacity of slaves as long as they remained in captivity. However, they could neither kill them nor keep them as slaves come what may.
    Three types of captives, however, were an exception to this rule:
    1. Brutal adversaries, as per the dictates of the law of  (itmamu’l-hujjah)⁴⁴, were required to be slain wherever found. Examples of people who were killed as a result were ‘Uqbah Ibn Abi Mu‘it, Nadr Ibn Harith⁴⁵ and Abu ‘Azzah⁴⁶ – the captives of the battles of Badr and Uhud. Similarly, at the conquest of Makkah, certain others were also slain as an exception to the general amnesty granted because of their open enmity.⁴⁷
    2. The captives of the Banu Qurayzah who met a fate decided by an arbitrator appointed by themselves: their men were slain and their women and children were sold as slaves.⁴⁸
    3. Captives who were slaves prior to their capture and, at certain instances, were distributed among people as slaves.⁴⁹
    It is obvious that these three cases were exceptions and the directive stated in the above quoted verse never related to them. Consequently, if all the incidents of the Prophet’s times regarding prisoners of war are studied, it can be safely concluded that barring these three exceptions everything done was in conformity with the above quoted directive of Surah Muhammad.
    Following are the details:
    1. As long as the prisoners remained in captivity of the state authorities, they were treated in a befitting manner. It is known that the prisoners of Badr were distributed among the Companions (rta) and the Prophet (sws) himself directed the Companions (rta) in the words:  (istawsu bi‘l-usara khayran: treat these prisoners well).⁵⁰ One of the prisoners Abu ’Aziz says that he was kept in a house of the Ansar tribe. He goes on to say that his hosts fed him with chapati while they themselves just ate dates.⁵¹ When Thumamah Ibn Uthal, a chief of Yamamah, was taken into custody, he, at the behest of the Prophet (sws), was fed with good food and milk as long as he remained in captivity.⁵²
    2. Most prisoners of the battle of Badr were set free after accepting ransom from them. Those among them who could pay in cash were exacted a ransom that ranged from one thousand to four thousand dinars per prisoner, while those among them who were not in a position to pay this amount were set free if they taught ten children each from among the Ansar to read and write. Abu Sufyan’s son, ‘Amr, was set free in exchange for Sa‘ad Ibn Nu‘man whom he had imprisoned.⁵³
    Among the captives of the battle of Bani Mustaliq, Juwayriyyah was freed after her father, Harith Ibn Abi Darar paid the ransom money.⁵⁴ Once Abu Bakr (rta) was sent on a military campaign. Among the captives there was a beautiful lady. The Prophet (sws) sent her to Makkah and was able to win the freedom of many prisoners in lieu of her.⁵⁵ Similarly, a prisoner of the Bani ‘Aqil was sent to Ta’if and in lieu of him, two prisoners in the custody of the Banu Thaqif were released.⁵⁶
    3. Some captives were set free without any ransom. Among the captives of Badr, Abu’l- ‘As, Matlab Ibn Hantab, Sayfi Ibn Abi Rafa‘ah and Abu ‘Azzah and among those of the battle against the Banu Qurayzah, Zubayr Ibn Batas were set free like this.⁵⁷ At the time of the truce of Hudaybiyyah, about 80 people from Makkah suddenly attacked the Muslims at night from the direction of Tan‘im. All of them were caught and the Prophet (sws) set them free without any ransom money as well.⁵⁸Thumamah Ibn Uthal, referred to earlier, was also set free on similar grounds.⁵⁹
    4. On some occasions, the prisoners were distributed among people so that they could directly deal with them or their relatives on the principle of  (fa imma mannan ba‘du wa imma fida’an: thereafter free them as a favour or free them with ransom), the prisoners of the battle against the Bani Mustaliq, were distributed thus. However, once the Prophet (sws) married Jawayriyyah after she had been set free, all the Muslims set free the prisoners in their custody without any ransom saying that these prisoners had now become the relatives of the Prophet (sws). Prisoners from about one hundred families were released in this way.⁶⁰ The prisoners of the military campaign (sariyyah) against the Hawazin tribe were also similarly set free by the Prophet (sws) without taking any  ransom from the people. Similar was the case of the prisoners of the Hunayn tribe.⁶¹
    When the tribe of Hawazin came to buy the freedom of their prisoners, it came to their knowledge that all their prisoners had been distributed. At their request, the Prophet (sws) gathered all Muslims among whom these prisoners had been distributed. When all had assembled, the Prophet (sws) expressed his opinion that everyone should release the prisoners they had in custody. He further said that whoever wanted to set them free without any ransom, should do so and others who wanted ransom would be granted the ransom by the state treasury. As a result of this request, 6000 prisoners were set free, and those among the Muslims who demanded ransom were paid by the state treasury.⁶²
    5. Widows and other helpless women among these prisoners who had been similarly distributed were generally set free by the respective owners and married to them through their free consent. On these very grounds, the marital knot was tied between Safiyyah (rta) and the Prophet (sws).⁶³