To labors other than circumcision, but circumcision supersedes it. A priest with a leprous spot may not offer the sacrifice. Leprosy is more powerful than the command to offer the sacrifices. Sacrifices are offered on Shabbat. Sacrifices supercede Shabbat.
Circumcision supercedes leprosy.
Logically, therefore, circumcision supercedes Shabbat. Perhaps the Sabbath is more stringent, since there are many penalties and injunctions in connection to it. Therefore in the day' is stated, teaching, even on the Sabbath. This is Raba's explanation of the writer of the previous paragraph's thinking. That leads to the following quote from another Tanna about circumcision and leprosy.