In Galatians 5:12, is Paul actually wishing that those wanting to impose circumcision would emasculate themselves?
The New King James Version renders this passage as: "I could wish that those who trouble you would even cut themselves off!" The New International Version states: "As for those agitators, I wish they would go the whole way and emasculate themselves!"
The word under consideration is apokopsontai. It is the third-person, indicative, future tense, middle voice form of the word apokopto. While this form of the word is only used in Galatians 5:12, other forms are used in Mark 9:43 (to cut off a hand), Mark 9:45 (to cut off a foot), John 18:10 (to cut off an ear), John 18:26 (to cut off an ear), and Acts 27 32 (to cut off ropes holding a boat). Thus we can see that the word means to cut off and what is being cut off is dependent on the context in which it is being used.
When the Septuagint translation was made, this word, apokopto, was used in Judges 1:6-7 (to cut off thumbs and big toes), II Samuel 10:4 (to cut off clothing), Deuteronomy 25:12 (to cut off a hand), Isaiah 18:5 (the cutting off of sprigs), and Psalms 77:8 (the cutting off of God's mercy). One of the Hebrew words, karath, that apokopto is used to translate, could also be used to refer to emasculation, as seen in Deuteronomy 23:1, "He who is emasculated by crushing or mutilation shall not enter the assembly of the LORD." But every use of apokopto did not refer to emasculation and every use of karath was not translated by apokopto in the Septuagint.
Experts in the Koine Greek do agree that apokopto can include the action of making a man a eunuch, based on its usage in other documents, especially when apokopto is used alone without an object. Early Christian writers, such as Jerome, Ambrose, Augustine, and Chrysostom, understood this passage as: "'Would that they would even cut themselves off,' that is, cut off not merely the foreskin, but the whole member: if circumcision be not enough for them, then let them have excision also," according to the Jamieson - Fausset - Brown Commentary.
However, as the Jamieson - Fausset - Brown Commentary notes, such an interpretation seems to be "an outburst hardly suitable to the gravity of an apostle." The word literally means "cut off themselves," but what is being cut is not defined in the word. Some of the newer translations assume that since Paul is speaking of circumcision in the context that he was referring to extending the cutting. The problem is that it is an assumption. It loses a possible play on words where Paul is saying that if people insist on circumcision, then they should go all the way and cut themselves off from the fellowship of Christians. The later matches other statements by Paul, such as, "Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law. You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace" (Galatians 5:2-4).
I suspect that both emasculation and separation are meant. Under the Old Law, an emasculated man could not be a part of the assembly (Deuteronomy 23:1). Paul is stating that the Judaizing teachers are causing problems by insisting on the continued practice of circumcision. It is such an annoyance that Paul could almost wish that instead of just circumcising themselves they emasculated themselves, which by the Law that they wish to enforce would mean they could not be a part of the assembly. Thus, he would be done with the problems they are causing. Thus, cutting themselves off (emasculating themselves) becomes a play on words for cutting themselves off (separating themselves from God's people).
It appears to me that it would be better for the translators to leave the vagueness of the term in the translation, as done in the New King James Version, than to make an assumption. Fixing it at emasculation loses the double meaning in English. Even if you want to argue that Paul meant emasculation only, the use of "I would wish" (ophelon: an unattainable desire) as the lead-in indicates that Paul is not wishing for actual harm; he is indicating that he is talking figuratively. Thus, we still end up with a figurative separation from the body (the church) and not a desire for physical mutilation.