“The Babylonian Talmud (Yebamoth folio 46a)…contains the tradition that Eliezer and Joshua, who both flourished toward the end of the first century A.D., disagreed in their views…. Rabbi Eliezer asserted that circumcision without immersion [as distinct from submersion], Rabbi Joshua that immersion without circumcision, was sufficient…. We thus have good authority for believing that proselyte baptism was practised towards the end of the first century [cf. too Matthew 23:15]….
“The necessity for proselyte baptism was argued by the Talmudic scholars from the fact that, according to Exodus 19:10-22, the Israelites were commanded ‘to sanctify themselves’ before the deliverance of the Law at Sinai…. In the case mentioned by Josephus (Antiquities 2:4), circumcision was simply remitted.” Thus Brandt.