פירוש על עבודה זרה 54:9

The irony of the story is that the rabbis say to him that he should be happy that he did not break a fence by being healed by a heretic, for such a person will be bit by a snake. But Ben Dama was bit by a snake! The Talmud answers by saying that the “bite of the snake” referred to in that saying is worse than the bite a real snake. The type of snake referred to in that saying is “the snake of the rabbis”—one bit by such a snake cannot be healed even in the world to come.