Circumcision
Circumcision is very important to most branches of Judaism, with over 90% of male adherents having the procedure performed as a religious obligation. The basis for its observance is found in the Torah of the Hebrew Bible, in Genesis chapter 17, in which a covenant of circumcision is made with Abraham and his descendants. Jewish circumcision is part of the "brit milah" ritual, to be performed by a specialist ritual circumciser, a "mohel", on the eighth day of a newborn son's life, with certain exceptions for poor health. Jewish law requires that the circumcision leaves the glans bare when the penis is flaccid. Converts to Conservative and Orthodox Judaism must also be circumcised; those who are already circumcised undergo a symbolic circumcision ritual. Circumcision is not required by Judaism for one to be considered Jewish, but some adherents foresee serious negative spiritual consequences if it is neglected.
John 7
In a discussion which demonstrates this point to the learned Jews, Jesus then refers to the Mosaic law, and to the law and tradition of the patriarchs. The law of circumcision prescribed by Moses () originated with God's covenant with Abraham and required every male child to be circumcised on his eighth day. If this day was a Sabbath, the obligation to circumcise that day overrode the obligation to rest on the Sabbath (). Jews familiar with both laws would also have been familiar with the rule of precedence between them. But Jesus then refers to the healing at the Temple on the Sabbath day of a man who had had an infirmity for thirty-eight years (), on account of which the Jews wanted to kill Jesus ():