פירוש על עבודה זרה 53:13

The Talmud reverses the positions back to their original arrangement. Now we have to solve the contradiction in the positions of R. Meir. The answer is that to R. Meir it depends on whether the doctor is an expert.

The final suggestion is that they disagree about whether a woman can circumcise. To Rav, she may not because she is not part of the covenant of circumcision. But to R. Yohanan she may because a woman does not need to be circumcised—it is as if she is already circumcised.