Daf Yomi - Yoma 83 - Story Regarding the Riva

The Radvaz (3:444) relates an incident regarding the Riva, one of the Baalei HaTosafos, who was ill with an illness that he eventually succumbed to. The doctor informed the Riva that if he were to fast on Yom Kippur he definitely would not be able to continue living and were he to eat, it would be possible that he could continue to live. The Riva was adamant in his refusal to eat on Yom Kippur and he subsequently died. The Radvaz writes that the Riva certainly did not maintain that one is permitted to be stringent with regard to his own health, as one is prohibited from disobeying the directives of the doctor. If one was coerced to violate a mitzvah in the Torah, if through his death HaShem’s Name will be sanctified, he is permitted to forgo his life. Rather, the Riva was aware that even if he were to eat he was not going to live and this is an illustration of the proverbial dictum that the heart knows the bitterness of its soul.