The Jewish Babylonian Talmud – Section Moed – Tract Sabbath – Regulations ordained by R. Eliezer concerning circumcision on the Sabbath.
p. 288 CHAPTER XIX. REGULATIONS ORDAINED BY R. ELIEZER CONCERNING CIRCUMCISION ON THE SABBATH. MISHNA: R. Eliezer saith: If the knife used for circumcision was not brought on the day preceding the Sabbath, one is to bring it publicly on the Sabbath; in times of danger (during persecutions) one may conceal it (about the person) before witnesses. Further,