Genesis 17 states that God required that Abraham and those of his house to be circumcised as a sign (NET “reminder”) of the covenant between God and Abraham and those who succeeded him.
Why did God initiate this specific procedure? What was its meaning?
The Bible does not give a reason why circumcision was chosen over other possible signs. Because it was a private sign, perhaps it diminished the temptation of making inappropriate public signs (see Matt 6:6).
It is sometimes said that circumcision was commanded because of the health benefits it confers. While there is evidence that circumcision does confer benefits, it also has risks. The Bible makes no claim about the health benefits of circumcision, and in particular, Christians are commanded not to require circumcision of others (Acts 15:19-20), so any health benefits cannot have been the primary motivation for the original commandment.