I am a Kohen and living in Israel I duchan every day. A member of the congregation where I daven with whom I have had some personal differences has informed me, in writing, that he does not wish for me to bless him. I was taught by my rabbis that a Kohen cannot exclude anyone from their blessing. Can I continue to bless the whole congregation even though it includes a person who has specifically asked me not to bless him?
The source of this law is in the Zohar Parashat Naso: We learn: Any Cohen who is not loved by the people should not Duchan. And there was an incident with one Cohen who got up and Duchaned, before he was finished, he turned into a pile of bones. And the reason was because he didn’t bless with love. A different Cohen got up, Duchaned and blessed. And it was instituted that day that a Cohen who does not love the people or the people don’t like him, he should not spread out his hands to bless the people as it is written (Mishlei 22) “Tov Ayin Hu Yevorach” [He that hath a bountiful eye shall be blessed] Al Tikri Yevorach Ella Yevarech [don’t say shall be blessed but should bless]. This Zohar is brought down in Halachah, that if the Cohen hates the congregation or vice versa, he should not Duchan due to danger. On this was instituted the Brachah “Levarech Et Amo Yisrael Be’Ahavah” [to bless his people Israel with love]. As Aharon HaCohen’s descendant who was a “Ohev Shalom Ve’Rodef Shalom” [loving peace and pursuing peace – Avot 1, 12] perhaps you should try to appease him and make up with him, so you should be able to continue Duchaning in your congregation. [זהר פרשת נשא דף קמז: מג"א סימן קכח ס"ק יח, והעטרת זקנים סוף סק"ח, ובחתם סופר על השו"ע, ובמ"ב ס"ק לז. וע"ע אליה רבה סימן קכח סעיף יא אות כו בשם תנחומא – נשא סוף פרשה י]. There is a saying – what is the reason that people thank the Cohanim after Duchaning, isn’t this their Mitzvah? They receive a Yasher Ko’ach not on the Brachah but on the love, that they blessed us with love.