‘And God said to Abraham, “And as for you, you will keep my covenant, you and your seed after you throughout their generations. This is my covenant that you shall keep between me and you and your seed after you, every male among you shall be circumcised. And you shall be circumcised in the flesh of your foreskin, and it will be a token of a covenant between me and you”.'
In Genesis 15 a sign was given to Abram in the form of a covenant ceremony where the blood of animals was shed to seal the covenant. Here that is replaced by the shedding of blood in person in each one who would enter the covenant. By being specifically circumcised with a view to membership in the covenant community they showed their response to God's covenant with His people and their commitment to the God of the covenant.
We note here that the respective positions are made clear. It is God Who ‘establishes' the covenant (Genesis 17:7). It is Abraham who ‘keeps' it (Genesis 17:9-10). Circumcision is not the making of a covenant but the response to a covenant already established by God.
The rite, which was restricted to males, was to be carried out on the eighth day after birth (Genesis 17:12) although any male who was uncircumcised and who wished to join the covenant community at any age was also required to be circumcised whether slave or free (Genesis 17:12-13).
We have unintentional confirmation of how ancient this ceremony is in Joshua 3:5 where we are told that Joshua used flint knives for the performance of the rite at a time when the use of metal was well known. It is clear from that that the ceremony was seen as so sacred that the original methods had to be followed. Moses' failure to circumcise his son led to almost fatal illness until the situation was remedied (Exodus 4:24-26). Again a flint was used. At the Exodus it is stipulated that the Feast of the Passover could only be celebrated by circumcised males (Exodus 12:44; Exodus 12:48).
Circumcision was an ancient institution not limited to the family tribe of Abraham and was practised in Egypt in the Old Kingdom period. But there it was carried out during boyhood rather than at infancy. A sixth dynasty Egyptian tomb relief depicts a boy being circumcised and two prisoners of a Canaanite king depicted on a 12th century BC Megiddo ivory were also circumcised. But it is clear that in Abraham's family tribe general circumcision was not practised up to this point, and it was not generally practised in Mesopotamia from where Abraham came. Modern medicine has shown the value of circumcision in protecting the health of those who live in semi-desert conditions as it helps to prevent foreign bodies becoming trapped under the foreskin.
Later the peoples round Israel are also seen to be in the main circumcised for the Philistines are disparagingly marked down as ‘the uncircumcised Philistines' (Judges 14:3; Judges 15:18), because their state was considered unusual and despised. How far this arose from connection with the covenant with Abraham (and later Moses) and how far from Egyptian and other influence we do not know. It is to be noted that the inhabitants of Shechem were recognised as being uncircumcised at the time of Jacob (Genesis 34). Thus we have here an example, as later with the sacrificial system, of a more general practise which is taken over and given specific meaning.
Circumcision would also become the symbol of the need for a purified heart - see Deuteronomy 10:16; Deuteronomy 30:6; Jeremiah 9:25-26. Just as ritual circumcision was the outward sign of entry into the covenant, so ‘spiritual circumcision' signified a genuine commitment of the heart to God's covenant and obedience to His commands. Without the latter the former was meaningless. Moses spoke of himself as having ‘uncircumcised lips' (Exodus 6:12; Exodus 6:30). This is probably metaphorical and demonstrates early usage of such an idea. It may mean that Pharaoh would see him as inferior, or be a reference to his lack of ability as an orator. It is signifying that he is not fit to do the task required.
“And he who is eight days old will be circumcised among you, every male throughout your generations, he who is born in the house or bought with wealth from any stranger, who is not of your seed. He who is born in your house and he who is bought with your wealth must necessarily be circumcised, and my covenant will be in your flesh for an everlasting covenant. And the uncircumcised male who is not circumcised in the flesh of his foreskin, that soul shall be cut off from his people. He has broken my covenant.”
To share in the benefits of God's covenant circumcision is now required. It becomes the symbol of response to and commitment to the covenant. It applies to all, both slave and free. This is confirmation that even the lowest of the low in the family tribe were seen as within God's covenant and therefore as His people. Refusal would mean excommunication or worse, but this is an emphasis on the totality of the requirement rather than being given as a practical alternative. It is not really facing people with a choice. The one who refused would be revealing himself as deliberately blaspheming God, but there is always the possibility of those who will take an extreme position. Compare the seriousness with which Moses' lapse was treated (Exodus 4:24-26).
We note again here how the covenant community was made up of nationals from many nations.