Judaism Genesis 17 & circumcision

[Jason]

The Jew said that only way that could happen would be if the Muslim converted to Judaism and then if the Muslim had been circumcised previously he would have to be re-circumcised with a knife of needle that would cause a little blood.

Do you agree?

Yes, I agree.

In Judaism, there must be an intention to fulfill a commandment in order for the commandment to be considered fulfilled. If a child was circumcised for whatever reason, it was not done with the kavanah (intention) of entering into the covenant from Sinai. It was performed for whatever reason (because Muslims do it; because Americans do it; whatever).

In order for it to be considered the rite of entering the covenant between God and the Jewish people, one would have to under what is called a hatafat dam brit, which is a symbolic circumcision performed by piercing the scar tissue from the original circumcision and collecting blood (on a piece of gauze, for instance) to be presented before a Jewish religious court (beit din) for the specific purpose of entering the covenant.

Circumcision may be performed for any reason at all. Only circumcision that is performed with the kavanah of upholding the Torah regulation (and this is demonstrated by the recital of a blessing that expresses intention) is counted as the specific type of required circumcision.