(ה) עֻבָּרָה שֶׁהֵרִיחָה, מַאֲכִילִין אוֹתָהּ עַד שֶׁתָּשִׁיב נַפְשָׁהּ. חוֹלֶה מַאֲכִילִין אוֹתוֹ עַל פִּי בְקִיאִין. וְאִם אֵין שָׁם בְּקִיאִין, מַאֲכִילִין אוֹתוֹ עַל פִּי עַצְמוֹ, עַד שֶׁיֹּאמַר דָּי:
(5) If a pregnant woman smelled [food on Yom Kippur], they feed her until she feels restored. A sick person is fed at the word of experts. And if no experts are there, they feed him upon his own request until he says: enough.
חולה מאכילין אותו על פי בקיאין אמר ר' ינאי חולה אומר צריך ורופא אומר אינו צריך שומעין לחולה מ"ט (משלי יד, י) לב יודע מרת נפשו פשיטא מהו דתימא רופא קים ליה טפי קמ"ל
§ It was taught in the mishna: If a person is ill and requires food due to potential danger, one feeds him according to the advice of medical experts. Rabbi Yannai said: If an ill person says he needs to eat, and a doctor says he does not need to eat, one listens to the ill person.What is the reason for this halakha? It is because the verse states: “The heart knows the bitterness of its soul” (Proverbs 14:10), meaning an ill person knows the intensity of his pain and weakness, and doctors cannot say otherwise. The Gemara asks: It is obvious that a person knows himself better than anyone else does. Why does this need to be stated explicitly? The Gemara answers: It is lest you say that the doctor is more certain because he has had more experience with this condition. Therefore, the verse teaches us that even so, it is the ill person who knows his own suffering better than anyone else.
מר בר רב אשי אמר כל היכא דאמר צריך אני אפי' איכא מאה דאמרי לא צריך לדידיה שמעינן שנאמר לב יודע מרת נפשו
Mar bar Rav Ashi said: Any instance where an ill person says: I need to eat, even if there are one hundred expert doctors who say that he does not need to eat, we listen to his own opinion and feed him, as it is stated: “The heart knows the bitterness of its soul” (Proverbs 14:10).