RobH_en_tn/gen/17/11.md

You must be circumcised in the flesh of your foreskin

Some communities may prefer a less descriptive expression such as "You must be circumcised." If your translation of "be circumcised" already includes the word for "foreskin", you do not need to repeat it. This can be made active. Alternate translation: "You must circumcise every male among you" (See: rc://en/ta/man/translate/figs-euphemism and rc://en/ta/man/translate/figs-activepassive)

the sign of the covenant

"the sign that shows that the covenant exists"

the sign

Possible meanings are 1) "the sign" or 2) "a sign." The first means that there was one sign, and the second means that there may have been more than one sign. Here the word "sign" means a reminder of something that God had promised.