I stumbled across this statement regarding the prohibition of freeing a non-Jewish slave in an online article quoting Gemara Brachos. I am just looking for some clarity and background as to the nature of this prohibition.
“The Talmud (Berachot 47b) states that Rabbi Eliezer once freed a non-Jewish slave, thus granting him the status of a full-fledged Jew, so that he could be the tenth man in a minyan. He did this, despite the prohibition of freeing a non-Jewish slave, because of the importance of the mitzvah of minyan.”