Topics covered:
Chapter 19, Mishna 3
An 8th day circumcision overrides Shabbos, but an uncertain 8th day cicumcision does not. Five examples of uncertainty: 1) uncertain gender because the baby is an “androginos”, 2) baby born at twilight Friday night, 3) the baby was born circumcised, compare with a convert who was already circumcised, 4) an “8 month” baby which is really jargon for a baby born with dagerous signs that it will not survive, and 5) one born by caesarean section who does not render the mother tamei, ritually impure, as does a natural birth.