Gittin 11 - Is it good to be divorced?
A man does not have to personally deliver the divorce (Get) to his wife; he can appoint a messenger. If, while messenger is on his way, the husband changes his mind, the Get becomes invalid, and the divorce does not happen. Thus, the husband can change his mind while the messenger is en route.
Why don't we say that it is good for the wife to become free, and therefore the messenger should acquire the Get on her behalf immediately, thus affecting the divorce? - That is because there are certain disadvantages in a divorce: the husband is no longer obligated to provide his wife with sustenance. The rule is that if something is unquestionably good, the messenger can acquire it on behalf of a receiving person, but not if there are minuses is such acquisition.
However, when the master sends an emancipation letter (also called Get) to his slave, he cannot change his mind. Freedom is unquestionably good, and the minute the messenger receives the Get, he acquires it for the slave, who now goes free - this is the opinion of the Sages. Rabbi Meir disagrees about the slave: his freedom has this drawback that the master won't feed him. And the Sages? - They say that the master is allowed to stop feeding his slaves anyway. This may not be wise and is not sustainable, but since the master has this right, the slave actually loses nothing when he becomes free.
Rabbi Meir said to the Sages, "But if he is a slave of Kohen, he loses the right to eat the Kohen's portion. So that is a disadvantage!" To this the Sages replied, "He loses it not because he is free, but because he is no longer the acquisition of a Kohen. So he loses nothing - therefore let him be free, the master cannot change his mind."
However, what about the slave of a regular Jew, not a Kohen, what does he lose by getting freedom? - He gains, by being able to marry a Jewess!! - No, he loses the availability of female slaves, who are cheap to get, available and permissive.
Art: The Freedom Ring by Eastman Johnson