Genesis 17:14

And the uncircumcised male who is not circumcised in the flesh of his foreskin, unless he have some one to circumcise him, that man shall be cut off from his people; he hath made My covenant to pass away.

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.
Rabbi Abraham ibn Ezra said: “his foreskin, which is known, for it is in the genital organ. But not so are the expressions: uncircumcised in the heart; uncircumcised lips; their ear is uncircumcised. All of these latter are in a construct state. 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, and “the foreskin of your lips.” But instead it says, And ye shall circumcise the flesh of your foreskin, 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..) The word “flesh” in the expression, uncircumcised in flesh, is a euphemism for the genital organ, just as in the verses great of flesh,, 16:26. and an issue of his flesh.

וערל זכר, and an uncircumcised male' the verse speaks of a Jew. The commandment as well as the penalty for non-observance applies only to Jews. The members of Avraham's household whom G'd had commanded Avraham to circumcise, do not in turn have to circumcise their own children - even if they obtained their freedom and were no longer member of his household. The only reason a Jewish household must consist of males who have been circumcised is to preserve the uniform nature of such a household. In the event such a slave in a Jewish household does not want to submit to circumcision, his Jewish master must sell him. The owner is given 12 months to persuade such a slave to undergo circumcision. (Yevamot 48)

שלא ימול את בשר ערלתו ונכרתה הנפש ההיא, the penalty for non-performance of this commandment becomes applicable only once the male in question has reached the age of performing mitzvot, i.e. is over the age of 13. His father - usually the one who has been responsible for such neglect - is not subject to the penalty of karet, but is treated as having neglected to perform an ordinary positive commandment.

ימול; the root is נמל, conjugation kal, as in ונמלתם. The penalty is premature death of the guilty party.

הפר; My covenant which I established with Avraham. This covenant applied also to the person who failed to observe this commandment even if he lived a thousand years after Avraham.