Birchas Kohanim On A Fast Day
‘Because of Intoxication…’
We learn in our sugya that a kohen who drank wine may not say Birchas Kohanim. For this reason, our Sages decreed that Birchas Kohanim should not be said during Mincha since a kohen may have drunk wine beforehand. This is the accepted halacha (Shulchan Aruch, Orach Chayim 129:1).
According to this reasoning, Birchas Kohanim should still be said during Mincha on fast days since kohanim will obviously not have drunk wine on those days. However, R’ Yossi (whose opinion is accepted) rules that if we were to allow Birchas Kohanim during Mincha on a fast day, it would be said during Mincha on regular days as well. To prevent this from happening, our Sages forbade saying Birchas Kohanim during every Mincha of the year – fast days included.
The Gemara, however, explains that during the era of the Talmud it was customary to daven Mincha in the early afternoon on a regular day, but right before nightfall on a fast day. Sincethe two times for davening Mincha differed, there was no longer a concern that kohanim would say Birchas Kohanim during Mincha on a regular day if allowed to say it on a fast day. Therefore, it became customary to say Birchas Kohanim during Mincha on a fast day.
Today, the custom has again changed – with people davening Mincha just before nightfall both on regular days and on fast days. In other words, there is once again a concern that if kohanim are permitted to say Birchas Kohanim during Mincha on a fast day they may start saying it during Mincha on a regular day as well.
Should we, therefore, return to the original halacha to never say Birchas Kohanim during Mincha?
A Matter Of Custom
The Chazon Ish (O.C. 20) ruled that we should not change the custom we received from the generations that preceded us. Birchas Kohanim should therefore be said during Mincha on a fast day (see also Teshuvos Rav Po’alim 4:5).
Early Mincha on a Fast Day
A further question can be asked. The permission to say Birchas Kohanim during Mincha on a fast day was based on the fact that on fast days, unlike the rest of the year, communities daven Mincha before nightfall. What if a particular community doesn’t? What if a particular community davens Mincha early on fast days as well?
Although he did not wish to publish this ruling, the Chazon Ish ruled in his own beis midrash that when davening Mincha early on a fast day, Birchas Kohanim should still be said. Birchas Kohanim is a biblical mitzvah, he said, and since we are only uncertain whether a rabbinic restriction forbids us from performing it, we should follow the certain Torah law (see Kehilos Yaakov 2; Teshuvos Rav Po’alim, ibid).