Why did Islam not ban slavery? During the days of the holy Prophet, Muslims used to force the prisoners of war into slavery. They even dealt the female captives among themselves as war-booty. The Qur'an even gave permission to Muslim men (the owner of the captives)to have sex with them (See Surah An-Nisa). Why is this? Is such practice still valid?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

A servant should always remember that he/she controls no advantage by himself/herself except whatever Allah may will.
Everything in his/her life is in The Hand of Allah and every organ of his/her body does act only by His order and providence; his/her sleep and wakefulness, rest and business, his/her hearing and eyesight, mind and reason, hand and leg, heart and stomach. So, his/her heart beats by Allah's favor and if it fails, he/she will breathe his/her last. In the same way, one's stomach digests food without one's will.

On the other hand, if we turn our face towards the sky and look at the stars in their orbits, galaxies in their circuits, each floating in its own orbit accurately and minutely, we believe that Allah, The Great and Almighty, has created everything in due proportion, whether we recognize it or not. But, the devil tries his best to cast misconceptions in Muslim's heart. Thus, the Muslim has to seek refuge with Allah from such doubts and whispers and then, to seek knowledge with the scholars.

As for your question concerning slavery, we state that at the advent of Islam, slavery was common among all nations, and there was no difference between enslaving people after lawful wars or aggression or by cheating a free person and then enslaving him/her through different tricks. Islam, as way of life, has laid down many legislations that help eliminate slavery. Among these are the following:

1. Prohibition of selling free people or enslaving them.

2. Limiting the sources of slavery to those resulting from lawful wars.

3. Organizing relations between masters and slaves. For example, Islam earnestly invites all masters to be very kind with their slaves, to treat them as their offspring and relatives, to feed them well, to clothe them nicely, and then, to not burden them with work. Allah Says (what means): {Worship Allah and associate nothing with Him, and to parents do good, and to relatives, orphans, the needy, the near neighbor, the neighbor farther away, the companion at your side, the traveler, and those whom your right hands possess. Indeed, Allah does not like those who are self-deluding and boastful.} [Quran 4:36]
In the same vein, the Prophet said: "Slaves are your brothers. Allah has put them to serve you. So, feed them with your food, clothe them as you clothe yourselves and burden them not with what they can not do, and if you do that, you are to help them." [Muslim]

Another Hadeeth reads: "He who treats his slave badly will not enter Paradise." A man said: 'O Allah's Messenger! Haven't you told us that the largest number of slaves and orphans will be among the Muslim Ummah? The Prophet said: "Yes, you are to honor them and to treat them like your children, and feed them from what you eat." [Ahmad]

A third Hadeeth shows us the Prophetic advice to one who was beating one's slave: "O Abu Mas’ood! Know that Allah has more competence than yours, with which you treat this boy." Then, Abu Masoud said: “I will not beat a slave again.” [Muslim]

In a sound Hadeeth reported by Imam Muslim, the Prophet did not beat anyone with his hand, neither a servant nor a woman, but he did fight (Jihad) in the cause of Allah. He never avenged any wrong done to him personally, but he did avenge a wrong violating divine commandments.

Another Hadeeth reads: "He who has (these) three qualities, Allah will conceal him (his bad deeds) and make him enter Paradise:

1. Treating the weak kindly and gently, (2) showing true and deep sympathy to parents, and (3) to be nice with a slave." [At-Tirmithi]

On his last day in the present life, the Prophet ordered the people to perform the prayers and be attentive to slaves. He repeated it several times.

On the other hand, the Prophet advised slaves to obey their masters and to perform their duties well and completely, promising them a double reward.

In a sound Hadeeth reported by al-Bukhaari and Muslim: The Prophet said: “Three people will be doubly rewarded: (1) One who has a slave girl whom he has educated well, treated kindly, freed her and then married her, this one will be doubly rewarded; (2) one from among the People of the Book who has believed in Muhammad's Prophethood; and (3) and a slave who performs Allah's rights and acts sincerely on behalf of his master.” 4. Islam has also set “a wide open door” for emancipation. The Prophet said: “He who frees a Muslim slave, Allah will free each of his bodily parts from Hellfire.” [Al-Bukhari and Muslim]

Allah Says (what means): {… And those who seek a contract [for eventual emancipation] from among whom your right hands possess - then make a contract with them if you know there is within them goodness and give them from the wealth of Allah which He has given you…} [Quran 24:33]

Another Hadeeth reads: “One who helps a person who fights Jihad in the cause of Allah or helps a debtor or a slave who has a contract of manumission, Allah will shelter him in His Shade (on the Day of Judgment), where there will be no other shade except His.” [Ahmad]

5. Allah, The Great and Almighty, has allotted in Zakah, one of the five pillars of Islam, one main portion for emancipation.

6. Islam also has laid down emancipation as an expiation for some acts such as: (1) unintentional killing, (2) al-Dhihar (injurious assimilation of wife to mother), (3) breaking an oath, and (4) intentional breaking of fast during the day of Ramadan.

From this factual information, it should be clear that slavery was to be eliminated in Islam. It is our view that when the Islamic Sharee’ah is practiced faithfully, slavery will eventually be eliminated; we might add, so will all other acts of man's inhumanity to man.

For more benefit on slavery, please refer to Fataawa 357964, 256111, 84431, and 82182.

Allah knows best.