...you shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between Me and you. He who is eight days old among you shall be circumcised, every male child in your generations, he who is born in your house or bought with money from any foreigner who is not your descendant. (Gen 17,11-12)

When God began to speak, and the word "covenant" was first uttered, Abram unconsciously remembered the first covenant, in which he sacrificed the animals and was then gripped by the darkness in which he had to drive away the vultures. At this moment, therefore, he instantly recalled the best parts of his flocks, with which he will honour the new bond between himself and God. He already knew well that the essential covenants would be made with the shedding of blood, because their observance was a matter of life and death.

But what was his surprise when God told him that this covenant would not be sealed with the blood of animals, but... his own!

Circumcision illustrates what we often see in God's dealings: God uses a custom that is commonly found in a given time, but modifies it and gives it a different, higher meaning. (We see the same thing later on, e.g. in the baptism, the Lord's Supper, etc.) Circumcision was practiced by several ancient nations, where (especially among the Egyptians) it served as an initiation ritual, a sign of accepting boys to become adult men. It was performed around the age of 12-13, when their sexual life was awakening, supposedly also with the aim of suppressing sexual activity. In any case, the Egyptians insisted on circumcision for many centuries afterwards - there is a famous case from history of a pharaoh who had a big problem to gain a respect of his subjects because he was not circumcised. And in the 6th century BC, when Pythagoras wanted to study ancient geometry treatises in Egyptian temples, he had to have himself circumcised, otherwise he would not have been allowed entry by the priests!

Even the nations who did not use circumcision (such as the Canaanites) certainly knew about the practice and its significance: a circumcised person had a different social status than an uncircumcised one. God took this concept and gave it a new meaning: circumcision would become a sign of the covenant, "marking" his people. But what is completely new: this change did not come later in life, but right at their birth. Each of the descendants of Abram and the members of his house is thus taken to a new level, simply by virtue of their descent; they acquire a new, higher status of which they can be justly proud - they belong to the Lord.