When R. Zera migrated from Babylon to Palestine, he fasted one hundred days, praying that he might forget the Gemara which he had learned in Babylon, so that he might learn the Torah properly in Palestine from R. Johanan.

Then he fasted one hundred days more, praying that R. Eliezer might not die before him, for

then the whole burden of communal work would fall upon him, since R. Eliezer was the head of the

community. Then he fasted one hundred days more, praying that he might be saved from the punishment of Gehenna. Every thirty days he tested himself by entering a burning limekiln, but

the fire did not touch him.

Once the sages expressed their envy of him in being safe from the fire of Gehenna.