To Fortunatus, Bishop.
Gregory to Fortunatus, Bishop of Neapolis (Naples).
We have written before now to your Fraternity that, if any [slaves] by the inspiration of God, desire to come from Jewish superstition to the Christian faith, their masters have no liberty to sell them, but that from the time of their declaring their wish they have a full claim to freedom. But since, so far as we have learned, they [i.e. Jewish masters], weighing with nice discrimination neither our wish nor the ordinances of the law, think that they are not bound by this condition in the case of pagan slaves, your Fraternity ought to attend to such cases, and, if any one of their slaves, whether he be a Jew or a pagan, should wish to become a Christian, after his wish has been openly declared, let not any one of the Jews, under cover of any device or argument whatever, have power to sell him; but let him who desires to be converted to the Christian faith be in all ways supported by you in his claim to freedom. Lest, however, those who have to lose slaves of this kind should consider that their interests are unreasonably prejudiced, it is fitting that with careful consideration you should observe this rule—that if pagans when they have been brought out of foreign parts for the sake of traffic should chance to flee to the Church, and say that they wish to become Christians, or even outside the Church should announce this wish, then, till the end of three months during which a buyer to sell them to may be sought for, they [the Jewish owners] may receive their price; that is to say, from a Christian buyer. But if after the aforesaid three months any one of such slaves should declare his wish and desire to become a Christian, let not either any one afterwards dare to buy him, or his master, under colour of any occasion whatever, dare to sell him; but let him unreservedly attain to the benefit of freedom; since he (i.e. the master) is in such case understood to have acquired him not for sale but for his own service. Let, then, your Fraternity so vigilantly observe all these things that neither the supplication of any nor respect of persons may avail to inveigle you.
Source: Register of Letters (New Advent)