"Imam Al Bukhari relates:
Az-Zuhri said regarding a virgin slave-girl raped by a free man: The judge has to fine the adulterer as much money as is equal to the price of the female slave and the adulterer has to be flogged (according to the Islamic Law); but if the slave woman is a matron, then, according to the verdict of the Imam, the adulterer is not fined but he has to receive the legal punishment (according to the Islamic Law). [14]
Here Imam Al Bukhari brings the statement of Imam Az Zuhri in which is specifcally speaks about the issue of a free man raping a female captive. He says that if the female captive is a virgin then the man should be punished with lashing but if she was previously married he should be executed (Hadd). This is clear evidence, from a scholar that studied under many Companions, that raping of female captives is prohibited in Islam. We also understand that this is the understanding of Imam Al Bukhari, that raping of female captives is impermissable, due to him bringing this narration and the statement of Imam Az Zuhri.
The next Hadeeth Imam Al Bukhari brings in this chapter is the following:"
But doesn't this hadith refer to any other free-man who rapes another person's slave?