Hiya folks,

Just a pre-emptive mod note that we're all well aware that the jury remains out on circumcision as GM, and that this is an extremely charged topic at the moment. /r/Askhistorians is not a place to soapbox about your thoughts on circumcision, so please be sure to direct your responses towards answering OP's question, which is with regards to the origins and methods of the practice.

Thanks!

Textually, this is mandated in the Bible: Genesis 17:9-14. As Jews take Abraham as their ultimate patriarch, this would apply to them.

I defer to the Ancient Near East historians to describe the observations of the actual practice, and rabbinical historians to describe the various 'whys' besides the text.