What is the ruling on a slave marrying a free woman, with or without the guardian's consent, or with only the woman's consent? And what are the conditions for applying the word "slave" to a human being in the current era, especially with the presence of those who say, "we inherited them"?

The Hanafis, Shafi'is, and the sound opinion among the Hanbalis hold that freedom is a condition for kafa'ah (suitability/equality in marriage), so a slave cannot be suitable for a free woman. They base their argument on the Hadith of Barirah. The Malikis differed on this matter; some of them permitted it, while others favored the view that a slave is not suitable for a free woman. Slavery is a legal disability caused by disbelief (kufr), and the original state of a human being is freedom.