Islam critiqued fights human exploitation: Did the prophet trade black slaves?

In answer to the video "Muhammad did it. Therefore it is not sinful."

The prophet did not "trade" in slavery. Under the hudaybiya treaty, any Muslim from Meccan fleeing to Medina where the Muslim community was established, had to be returned to the Meccans. It was in such circumstances that a person whom the prophet did not know was someone's slave, sought refuge with him. When the Meccan master came looking for him, he would not return until the prophet gave him 2 of his own, and of his, the Meccan's, choice. The 2 chosen by the Meccan were black. He chose the best in his sight and although the bargain was not ideal for the prophet, he showed that he valued his own much more than his opponents valued theirs.

A report from Zad al Maad by ibn Qayyim, speaking of the prophet buying and selling slaves, gives a single example of such "transaction" which is none other than the one already spoken of by Bukhari above. As to the prophet buying slaves this is of course attested many times in the authentic reports, he bought them from other Muslims following their capture as war prisonners, to immediately emancipate them and set the example. The report from Zad al Maad gives other details which are dismissed by the hadith scholars, including Bukhari as inauthentic. This is mentionned in the footnotes of ibn Qayyim's complete version of Zad al Maad p163-165.