The Literal Commandment
On the eighth day the flesh of his foreskin shall be circumcised.
(Leviticus 12:3)
Given in the same passage that deals with the birth of a male child, this commandment to circumcise is only for male children.
Messiah Says
In John 7:22-23, Messiah affirms the commandment to circumcise male children on the eighth day... even if that day falls on the Sabbath. He affirms the commandment and uses that position to validate His work of healing and making "an entire man well" on the Sabbath.
Pictures of Messiah
Circumcision pictures Messiah in that salvation requires circumcision... not of the flesh but of the heart (Deuteronomy 30:6, Jeremiah 4:4).
The Messiah is our salvation. In fact, His Hebrew name, Yeshua, means "salvation".
How Messiah Fulfilled
Messiah's mother and adoptive father were very devout Jews and circumcised their son on the eighth day according to the commandment:
And when eight days had passed, before His circumcision, His name was then called Jesus, the name given by the angel before He was conceived in the womb. (Luke 2:21)
Although Messiah did not fulfill this commandment by His own effort, His parents had Him circumcised according to the commandment.
Traditional Observance
All male infants are circumcised on the eighth day unless serious medical conditions prohibit it from occurring. In those circumstances, the child is circumcised as soon as his health permits it.
One highly regarded source of Jewish understanding regarding the commandments, Sefer HaChinuch, offers this insight:
One root reason for this precept is that the Eternal Lord, be He blessed, wished to affix in the people that He set apart to be called by His name, a permanent sign in their bodies to differentiate them from the other nations in their bodily form, just as they are differentiated in their spiritual form, their very "exits and entrances" [their purpose and way in this world] not being the same. This [physical] differentiation was set in the golden orb as it is the causal source of the existence of the [human] species...1
By making this distinction "in their bodies" G-d provided a physical identifier marking the uniqueness of His people.
Other Notes
We are able to fulfill this commandment today and should circumcise our sons on the eighth day after their birth (allowing for the health of the child).
248 of the 613 commandments are positive in nature:
the commandment tells us to do something
- versus -
the commandment tells us not to do something
This commandment to circumcise a male child is only one of two positive commandments that bears the penalty of being "cut off" [Hebrew: karat] from the people of Israel if that child is not circumcised.
The responsibility to circumcise a male child is incumbent upon the father of the child and not the mother. If the father is not present then the responsibility traditionally falls to the judges [beit din] of the child's town.
If a child is not circumcised by the time he reaches the age of accountability (traditionally 13 years and a day) then the responsibility to become circumcised becomes his. If he dies while still uncircumcised then the penalty of karat falls upon him. The penalty of karat does not fall on the father.
The other positive commandment that bears the penalty of being cut off [karat] is the commandment to eat unleavened bread during the week of the Festival of Unleavened Bread [Chag HaMatzot] (Exodus 12:15).
