The hard truth is that Islam did not announce a one-line legal ban on all slavery in the seventh century. Its answer was to restrict its sources, humanize those already trapped in it, and make emancipation a repeated act of worship and expiation.
Why critics find this hard
The objection deserves to be stated strongly. If slavery is a grave moral wrong, why would revelation regulate it instead of simply saying, "No one may own another human being"? The critic also points to reports where the Prophet (PBUH) dealt with slaves as part of the legal economy of his time, including the hadith in which a master came for his slave and the Prophet (PBUH) said, "Sell him to me," purchasing him for two black slaves. That is not a minor detail; it shows regulation, not outright abolition.
So the question is not whether Islam improved slavery. It plainly did. The sharper question is whether improvement is enough for a religion claiming divine guidance.
What the Quran actually set in motion
The Quran did not treat slavery as a natural racial order, nor as a permanent ideal. It attacked the surrounding system at several points: freeing slaves became a major virtue, an expiation for sins, and a path to divine pleasure.
"And what can make you know what is the difficult path? It is the freeing of a slave."
Quran 90:12-13
"And those who seek a contract for emancipation from among those whom your right hands possess - then make a contract with them if you know there is good in them, and give them from the wealth of Allah which He has given you."
Quran 24:33
The Sunnah also stripped ownership of its old meaning. A slave was not to be starved, beaten as a beast, sexually exploited through prostitution, or treated as outside the moral community. The Prophet (PBUH) said:
"Your servants are your brothers whom Allah has placed under your authority. Whoever has his brother under his authority should feed him from what he eats and clothe him from what he wears."
Sahih al-Bukhari and Sahih Muslim
He also taught that selling a free person is a crime before God:
"Allah said: I will be the opponent of three on the Day of Resurrection... a man who sells a free person and consumes his price."
Sahih al-Bukhari
The report about buying a slave
The hadith in Sahih Muslim 1602 is real. A slave gave allegiance to the Prophet (PBUH), apparently without the Prophet (PBUH) knowing he was a slave. When the owner came, the Prophet (PBUH) bought him in exchange for two black slaves. This shows that the Prophet (PBUH) operated within a society where slavery still had legal recognition. It does not help to deny that.
But it also must not be made to say more than it says. It is not a command to enslave people. It is not racial slavery. It is not kidnapping, plantation slavery, or the Atlantic slave trade. Classical Islamic law forbade enslaving free persons and treated unlawful enslavement as a major injustice. The remaining legal category was tied, in the main, to war captives in a world where every empire took captives and where there were no modern prisons, refugee systems, or international conventions.
Even there, the Quran placed release and ransom at the center of the discussion of prisoners:
"Then either confer favor afterwards or ransom them until the war lays down its burdens."
Quran 47:4
What this proves and what it does not
The objection proves that Islamic texts did not abolish slavery by a single explicit legal sentence. A Muslim should admit that plainly. It also proves that slavery persisted in Muslim lands, sometimes in ways that violated Islamic limits and sometimes under juristic permission.
But it does not prove that Islam morally sanctified slavery as an ideal. The direction of the Quran and Sunnah is unmistakable: close the doors of unjust enslavement, honor the enslaved as human beings, encourage and require manumission, and make freedom a religious good. The New Testament reference to "enslavers" is about kidnappers or slave-dealers who seize free people; Islam condemns that too.
So the fairest answer is this: Islam regulated a deeply embedded institution while pushing it toward contraction and emancipation. That may not satisfy every modern critic, but it is very different from saying the religion endorsed slavery as a timeless moral good.