This practice has always been strange to us, even those who bear the mark of circumcision. It seemingly is the last thing a man should want to do, yet interestingly it is a symbol of the very thing he wants to do.
Abram was a man called out of his fathers house from the city of Ur of the Chaldeans and led into the land which the Lord had prepared for all his descendants. Abram was accompanied by his relatives and their slaves and their children, free and slave and all who had joined themselves to Abram.
Insomuch as we may derive from this knowledge that they had a common understanding having been from one nation and even further one city. According to the nature of God, we must presume that the covenant which He would construct with Abram was one that would have symbolic meaning and peculiar depth. So, let's look at how the Chaldean would perhaps perceive the practice of circumcision.
The head of the penis, as is commonly accepted, is a mystical symbol of the head itself. However, just as today one might presume, so too then was the head synonymous with the heart. So, circumcision is the removal of the crown which crowns the head. This would lead us to assume it is symbolic of recognition of a superior crown or even a foreshadowing of that saying that we will cast our crowns before the Lord, even as Zipporah cast the foreskin of Gershom at the feet of Moses her husband who was confronted by the Lord; therefore casting that fleshy crown before the Lord as an appeasement.
Then, as well, we must assume that it could be percieved simultaneously as a hood or a sack which had shrouded the head and heart of the man. That same shroud of sin which man did don originally in the garden. God was calling them, perhaps, to display the removal of depravity and ignorance. Circumcision was almost certainly a symbol of enlightenment, seeing that the head was no longer covered and could now see the truth and the heart could feel all things as they truly are.
There is, now, another reason for circumcision which is perhaps just as blessed as the others. The Semitic people known as the Habiru (Hebrew), which is a Semitic term that embodies simultaneously vagabond, nomad, gypsy, and stranger, grew very quickly as a nation. Anyone who was a run away, a freed slave, a man-slayer, a merchant, any refugees could join themselves to the Habiru. They were in fact a frightening force, looked at as locusts in the countries in which they wandered into. However, the kings of varying cities sought to make use of them by making buying them as military allies, which is demonstrated in the Book of Genesis.
However, to create a uniformity in the society and to preserve their culture, circumcision would have been an effective deterrent against all those who were not worthy of character to dwell with the Habiru. The lack of courage to under go the surgery would have presumably been a disqualifying factor. It was a means of preservation, I think, that God wisely instated. Further, it is evident that circumcision is the healthier of choices in that it prevents the spreading of disease. Men who are circumcised are less likely to instigate cervical cancer in their partners. It was a symbol that these people were conceived in truth and understanding, where as the rest of the world was conceived in darkness and ignorance.
Also, we see the males only receiving the circumcision, though female circumcision did exist, but not among the Habiru. This is most probably because God stated the males, but secondly and less importantly, many primitive societies believed that the man made people and planted them in the woman (the homunculus). However, I can not speak certainly concerning the Habiru on this particular view, but it does to appear to have been the common consensus. This would reinforce the idea that the offspring would be conceived in knowledge of God, owing their generation to the male in the primitive mind. Anyway, just something to think about... ponderings, you might say.
"Every art and every inquiry, and similarly every action and choice, is thought to aim at some good; and for this reason the good has rightly been declared to be that at which all things aim." ~Aristotle~