142. A Kohein Who Isn’t Fasting
23:15 On a public fast day, when we read from Exodus chapters 32 and 34, we only call people who are fasting for aliyos. If the only kohein present is not fasting, or if he does not intend to complete the fast, then a Levi or a Yisroel is called for the first aliyah instead. In such a case, it is preferable that the kohein step outside for the aliyah. (If the kohein prefers not to go out on very minor fasts such as BeHaB, there is no concern that his being passed over for an aliyah may be perceived as a defect since it is known that not everyone fasts on these days. However, on the days when everyone should fast, if he does not go out it may be perceived as a defect – Mishnah Brurah 566:21.) If a fasting kohein is present, the non-fasting kohein need not step out but he should inform the gabbai not to call him up. If he should happen to be called, he should not accept the aliyah. If the fast is on a Monday or Thursday (at Shacharis – MB 566:21), the kohein may accept the aliyah if he happened to be called. This is because, even though the portion for a fast day is being read, the Torah would have been read on these days in any event.
23:16 The same applies to one who lives in Israel, where only one day of yom tov is observed (except for Rosh Hashana). If he is visiting outside of Israel on the second day of yom tov, he should not be called for an aliyah. The course of action is the same as for a non-faster on a public fast day.