פּירוש אויף בראשית 17:14

וערל זכר AND THE UNCIRCUMCISED MALE — This phrase teaches that circumcision must be at that place where the distinction between male and female is evident (Genesis Rabbah 46:13).

AND THE UNCIRCUMCISED MALE. Here Scripture teaches you that this circumcision must be at the location where the distinction between male and female is evident. Thus the words of Rashi. Our Rabbis have likewise mentioned other reasons.⁴¹⁸Shabbath 108a.
Rabbi Abraham ibn Ezra said:⁴¹⁹In his commentary to Leviticus 12:3. “his foreskin,⁴²⁰Leviticus 12:3. which is known, for it is in the genital organ. But not so are the expressions: uncircumcised in the heart;⁴²¹Jeremiah 9:25. uncircumcised lips;⁴²²Exodus 6:12. their ear is uncircumcised.⁴²³Jeremiah 6:10. All of these latter are in a construct state.⁴²⁴But when the word orlah is not used in the construct state (as in Leviticus 12:3) it refers to the genital organ.
In my opinion the matter is clearly explained in Scripture. It does not say, “And ye shall circumcise your foreskin,” thus leaving the meaning in doubt, nor does it say, “the foreskin of your flesh,” just as it says the foreskin of your heart,⁴²⁵Deuteronomy 10:16. and “the foreskin of your lips.”⁴²⁶I did not find this exact quote. Perhaps reference is to Exodus 6:12, mentioned above. But instead it says, And ye shall circumcise the flesh of your foreskin,⁴²⁷Verse 11 here. meaning that you are to cut off the flesh which is your foreskin, namely, your flesh which obstructs, and there is no flesh in the body which obstructs and covers a limb [as is the case with the genital organ], where one can cut the flesh and remain without the foreskin, other than the “flesh that covers the corona,” which the Sages mentioned.⁴²⁸Shabbath 137a. In our text of the Mishnah there: “flesh that covers ‘the greater part’ of the corona.” Ramban’s version is similar to that of the Talmud Munich Ms. (See Dikduke Sofrim, ibid.) The word “flesh” in the expression, uncircumcised in flesh,⁴²⁹Ezekiel 44:9. is a euphemism for the genital organ, just as in the verses great of flesh,⁴³⁰Ibid., 16:26. and an issue of his flesh.⁴³¹Leviticus 14:2. The word “flesh” in these two verses refers to the genital organ.

"הפר" in two senses in the text. On one hand, it means "break," and on the other hand, it means "violate his commandment." The Midrash explains it as drawing a comparison between the breaking of the foreskin during circumcision to the breaking of an animal's neck. Just as the neck is broken during the sacrifice of an animal, so too does one violate the commandment of circumcision by not circumcising.

אשר לא ימול HE WHO DOES NOT CIRCUMCISE HIMSELF) as soon as he reaches the age when he is legally liable to punishment, ונכרתה THEN HE SHALL BE CUT OFF — his father, however, who did not have him circumcised is not punished on his account with כרת (excision, “being cut off from his people”), but is merely transgressing an עשה “a positive commandment” (for which the punishment is flagellation).