Genesis 17:14 – And an uncircumcised male, who will not circumcise the flesh of his foreskin-that soul will be cut off from its people; he has annulled My covenant.

Gemora Sanhedrin 59b: From the verb “annulled” we learn that this verse includes the sons of Keturah in the requirement to be circumcised.

Torah Temimah Colloquial Translation on Note #46

It is not clear how this verse alludes to the idea that the sons of Keturah are obligated in the commandment to be circumcised. Further, I haven’t seen any commentators who attempt to explain this, even superficially. It appears to me that [perhaps] it can be explained based on the grammatical meaning of the verb “annul”. According to grammarians, “annul” [הפר]  refers to something that is totally null and void. This can be contrasted with the word “invalidated” [בטל] which refers to something that is declared void for a given period of time, but might be renewed or return to be valid. See Tosafot in Gemora Shabbat 20b.

So, consider that a Jewish person who is not circumcised for whatever reason, is more referred to as invalid rather than annulled. Thus, for example, it is possible that he might circumcise his own sons and resuscitate the commandment of circumcision [in his family] for later generations. This is not the case with the sons of Keturah, according to Rashi. Rashi’s opinion is that the obligation for the sons of Keturah is only on the six sons of Keturah explicitly mentioned [in verse Genesis 25:2]. In other words, the sons of Keturah were not commanded to be circumcised in perpetuity, but rather just her immediate sons. Therefore, if for some reason they were not circumcised, whether by accident or with intent, then the commandment of circumcision would be wiped out [from that family]. There would be no further command to circumcise her [later] descendants. As we explained above, this complete nullification is what is referenced with the word ‘annul’ and thus we see how this verse alludes to the sons of Keturah.

However, the opinion of Maimonides in Chapter 10, Halacha 10 in the Laws of Nations states that the sons of Keturah are obligated in perpetuity to circumcise their sons. Thus, according to his point of view, it does not make sense to say that the verb “annul” refers to the sons of Keturah. One could perhaps say that the reason the verse is teaching regarding the sons of Keturah is not due to the verb “annul” but rather due to the word “et”. [Editor’s note: this connecting word has no translation, it is used to indicate a direct object for a verb.] Thus, according to Maimonides the use of the word “et” [which is optional] refers to an additional inclusion in the command. The additional inclusion being the other wife of Abraham. Normally, the children of the maidservant [secondary wife] would be considered her children rather than the father’s children. [That would be why a special command was needed to state that the sons of Keturah are included in the commandment of circumcision in perpetuity.]

The core disagreement between Rashi and Maimonides is whether the sons of Keturah are commanded in perpetuity or not. The Shaagas Arye wrote at length on this issue. It appears to me a slight proof to Rashi from the Midrash concerning Yitro {Moshe’s father-in-law]. The Aggadah (Section 94:1) states that when the verse states that Yitro “joined” (ויחד) the Jewish people, he passed a sharp (חדה) sword over his flesh. {Meaning that he circumcised himself at that point.] Further, it is stated in Seder Olam Rabba and in Midrashim that Yitro was descended from Keturah. Thus, we see that Yitro did not circumcise himself until he decided to join the Jewish people. This would be a support for Rashi’s point of view.

Also note that Rashi exact phrasing is not entirely clear. Rashi states that this verse “comes to include the sons of Keturah, only those six alone and not in perpetuity. But Abraham was commanded for everyone who was born to him in perpetuity.” It is not clear what Rashi meant by adding the phrase “but Abraham was commanded…” In fact, this [additional] phrase is hard to understand. It appears that it was unclear to Rashi himself how it would be possible that the sons of Keturah were not commanded in perpetuity. The choice would seem to be either the sons of Keturah are from the seed of Abraham, then why would they not be commanded in perpetuity. Or, they they aren’t counted as “seed of Abraham”, then why would they themselves be obligated to be circumcised? It is for this reason that Rashi explains that they are not considered as “seed of Abraham”. If you would then ask why then do they have to be circumcised themselves, the answer would be “Abraham was commanded for everyone who was born to him…” This answer seems a little forced.

Editor’s Note: I think that it is interesting that Rashi and Maimonides have different opinions as to whether or not the sons of Keturah (and their descendants) are commanded to be circumcised.