Heart surgery

Tonight I attended a group that was discussing a letter purported to have been written by Barnabus in the first century. One of the topics from one of the chapters was circumcision. I know what that is because I have been. But it was being applied to the heart, not to the penis. I am wondering about the symbolism here. I think that circumcision is done for health reasons if it is not related to religion or identification to a particular cause or sect. Now when dealing with matters of the heart, I am losing a lot of the symbolism. Is circumcision of the heart a health matter? Or does it mean that my heart is identifying with a cause such as having major ethics? Does it mean having a clean heart? Whatever it is, the circumcision is a request from the creator about the inner person I have developed. Developing character usually hurts in some way. So, in that way I know I have been circumcised.