R. Yaakov Koppel Zeligson was the son of R. Avraham, the Rov of Lubavitch during the nesius of the Rebbe Maharash. R. Koppel was a chossid of the Rebbe Maharash and the Rebbe Rashab, and he served as a choizer for the Rebbe Rashab during 5652-53. He worked in Tomchei Temimim for some time as a mashgiach for Chassidus, and then as a secretary and bookkeeper in the Yeshivah’s administrative office. As a resident of Lubavitch, R. Koppel had a close relationship with the Rebbeim, and he is one of the witnesses signed on the Frierdiker Rebbe’s tenaim.
On a visit to Italy, the Rebbe Rashab was accompanied by R. Koppel and R. Avrohom Babroisker. Their host served them a new and unknown fruit, and they all recited a Shehecheyanu and ate from it. The taste was so repulsive that R. Koppel and R. Avrohom barely swallowed the first bite, but the Rebbe Rashab continued to eat from it, while deep in thought.
Suddenly, the Rebbe noticed that they weren't eating and asked if there was some halachic shaila with it. R. Avrohom, who was by nature a bittuldike person, did not have the courage to respond. But R. Koppel, who was quite comfortable, told the Rebbe that it was halachically okay, but "we simply can't put it in our mouths!"
The Rebbe then tasted some more, and concurred with them, and stopped eating.
