What is the reason that the ear had to be pierced rather than any other limb of the servant’s body? Rabban Jochanan ben Zaccai said: That ear which heard on Mount Sinai, (Exodus 20:13) “Thou shalt not steal” and yet its owner went and stole and was therefore sold as a slave — let it be pierced! Or, in the case of him who sold himself from destitution, having committed no theft, the reason is: That ear which heard on Mount Sinai what I said, (Leviticus 25:55) “For unto Me the children Israel are servants” and yet its owner went and procured for himself another master — let it be pierced! (Mekhilta d'Rabbi Yishmael 21:6:3; Kiddushin 22b). Rabbi Simeon interpreted this verse like a jewel (i. e. giving it an ethical signification): In what respect are door and doorpost different from all other objects in the house that they should be singled out for this purpose? God, in effect, said: door and doorpost that were eye-witnesses in Egypt when I passed over the lintel and the two doorposts, freeing Israel from slavery, and when I said, (Leviticus 25:55) “For unto Me the children of Israel are servants” — servants to Me but not servants of servants (of human beings), and yet this man went and procured another master for himself — let him be pieced in their presence (i. e. let them be eye-witnesses now when this man voluntarily prolongs his state of slavery)! (Kiddushin 22b.)
And then on the same verse writes:
AND HE SHALL SERVE HIM FOR EVER — This means until the Jubilee.
Given that lengthening one's servitude was greatly frowned upon, so much so that it seems to be a transgression of the whole concept of "Eved Hashem", would such a slave, once freed by the Yovel, need to do Tshuva on this? And if yes, would this require a korban?