One place is the 4th Chapter, specifically the verse of muta and the verses that precede it and go after, but there is other places as well if you keep in mind marriage is a form of "who your oaths give authority (to have sex with)" and Muta is said to be aside from marriage, a form of who our oaths give us authority to have sex with, which is halal dating but with conditions to safeguard any offspring that can come as a result.
Here I wrote this before:
I am going to be talking a lot of technical issues here, but I believe now, after much reflection, the issue of Muta, is all over the Quran, and is different then normal marriage.
Marriage is a type of long term version of "malakat Aymaanihim" (who your Oaths give authority regarding) but there is a non-long term commitment version of this, and I will be going through why I believe Quran has been mistranslated in this regard.
Aside from the absurdity of slave-owning, there is an issue, which some Quranist said, but doesn't make sense, that perhaps some people who needed a place to live where entrusted to Muslims. But that doesn't make sense that men have right to have sex with them, especially if those women are married themselves.
The problem with translating it as slave or right hand possessing type interpretation occurs in extreme in the following verse:
And all married women except those whom your right hands possess (this is) Allah's ordinance to you, and lawful for you are (all women) besides those, provided that you seek (them) with your property, taking (them) in marriage not committing fornication. Then as to those whom you profit by, give them their dowries as appointed; and there is no blame on you about what you mutually agree after what is appointed; surely Allah is Knowing, Wise. (4:24)
Another way to translate 4:24 in begining...is as follows:
And all married women (are forbidden to you) except those who your Oaths hold..
This is already seeming better why?
Well in the 1st translation, it would mean we are allowed having sex married women that are slaves. That is if two slaves are married - we can have sex with the poor slave's wife if we want to. Such absurd interpretation occurred in hadiths, but never mind them for this one second and let's read it rationally!
Say slavery was forbidden and condemned, as I do believe other verses outright to do so.
What can this mean? It would mean "All Married women except those who your Oath hold...", meaning except who you are married to from them.
This is all already a lot more rational then being able to have sex with a married slave woman!
Next, it continues:
, and lawful for you are (all women) besides those,
This means there is category aside from Married women.....so this means there is category of who your Oaths hold that is allowed, and so the verse here is the right place now to introduce the Muta:
provided that you seek (them) with your property, being of good will to them not committing fornication therefore to those whom you do muta to, give them their reward as appointed; and there is no blame on you about what you mutually agree after what is appointed; surely Allah is Knowing, Wise.
This verse talks about what was known historically as "Muta" but it was never that clear to me, till, I realized that Quran does outright forbid slavery.
The purpose of Muta then is emphasized in the verse that follows:
And whoever among you has not within his power ampleness of means to marry chaste believing women, then of those whom your oaths hold authority from among your believing maidens; and Allah knows best your faith: you are (sprung) the one from the other;
That is the purpose of Muta, if we can't get married because we don't have the means or circumstances make it hard, we can have Muta.
The verse then emphasizes on marriage:
Therefore marry them with the permission of their family,
That is you can do muta but if you are going to get married, you still need to ask the permission of their family!
and give them their dowries justly, they being chaste, not fornicating, nor receiving paramours; and when they are taken under good treatment, then if they are guilty of indecency, they shall suffer half the punishment which is upon married women. This is for him among you who fears falling into evil; and that you are patient is better for you, and Allah is Forgiving, Merciful.
Now every verse it makes more sense. It's always reminding "except their wives or who their oath's possess".
Now you see, the translations as slavery, it can be a good reason to reject Islam.
We live in a time - where we know how evil slavery is and it's hard to see these verses to be from God if they are indeed about slavery.
There is no reason to really though.
Instead it emphasized on "Muta".... and so the Quran explained with Muta exactly what the other category of who are Oath's possess are aside from who we marry, there is a 2nd category which is also allowed and it's called "muta" which means "enjoyment (that ceases)" .