According to the Hebrew Bible, in the Book of Genesis 17:1-14,
circumcision was enjoined when God says "Walk before Me and be
perfect" to the Biblical patriarch Abraham to be followed by his
descendants as "a token of the covenant" concluded with him by God
for all generations. It is also when his name is changed from
"Abram" to "Abraham" by God:
http://en.wikipedia.org/wiki/Brit_milah
Male circumcision existed before the birth of the Prophet Mohammed
and this custom is religously practised by Muslims as a precedent
of the Prophet, which is called the SUNNAH. In the index of an
authentic English translation of the Holy Quaraan, with Arabic
script, circumcision was not listed. However, every Muslim is
expected to follow the way of life of Prophet Mohammed (be peace
upon him). Therefore, all Muslims - devouts, liberals or seculars -
observe this ritual. Muslims are obliged to follow not only Allah's
message in the Holy Quaraan but also what the Prophet said or did,
as a proof of their dedication to Islam.
http://www.familymedicine.co.uk/features/circum3.htm
