In the introduction to the book "Amudei Esh Beis Yosef" by Hagaon Rav Yosef Leichtag, printed in Munkatch 1939 an interesting story is brought down regarding what occurred during the era of the heilige "Chozeh" of Lublin, Ztza"l.
It was a very difficult year due to war conditions, and the Esrog merchants could not import enough Esrogim into Poland as usual. There was a severe shortage, and the prices of Esrogim rose extremely high. Merchants demanded a hundred silver Rubles even for a simple Esrog.
The great Torah leaders of Poland held a gathering, an Asifah and decreed that each community was permitted to purchase only one Esrog using community funds. This decree took root in all communities, and throughout the Ten Days of Repentance, Aseres Yemei Teshuva, each town bought only a single Esrog and handed it over to the Rabbi. An order was established: First the Rabbi would recite the blessing over the Esrog, then the community leaders, and then the entire congregation. During Hallel, only the Chazzan and the Rabbi would perform the ceremonial waving, Na'anua'im, and no one else, so that the Esrog would remain preserved.
However, the "Chozeh" of Lublin possessed his own personal Esrog, which a Chosid had sent him from Germany before the decree of the leaders of the generation was issued. As soon as the Rabbi of the city of Lublin, the Gaon Rabbi Ezriel Horowitz (known as the "Iron Head or the “Eizener Kop", found out on the eve of Yom Kippur, he sent word to the Chozeh of Lublin that as the Chief Rabbi of the city, he forbade him from using his private Esrog due to the communal decree.
Naturally, the heilige Chozeh felt immense distress from this so much so that he could not compose himself to eat the pre-Yom Kippur meal due to his grief over the Esrog. Present at that time was the great scholar Rabbi Yosef Lichtag of Zebaruz, known as "Rabbi Yossel Charif" (the Sharp One), one of the prominent disciples of the Chozeh of Lublin. Rabbi Yossel spoke up and told the Rebbe not to worry, for he would settle the matter with the city's Chief Rabbi. Rabbi Yossel hurried to the "Iron Head" and told him that the Rabbi had overlooked an explicit Talmudic passage in Gemarra Chullin (17a).
The Talmud relates that the Jews in the wilderness were not required to ritually slaughter, do Shechita, on their cattle; they performed “Nechirah" (stabbing/slitting). Only upon entering the Land of Israel were they obligated to perform proper kosher slaughter as commanded by the Torah. Rabbi Yirmeyah asked a query: What about people who still possessed meat from the wilderness that was not ritually slaughtered, and brought that meat into Israel? Were they permitted to eat it in Israel, or did the old meat become forbidden once they entered the Land?
The Rosh, Rabbeinu Asher, on the spot (chapter 23) asks: What practical difference does Rabbi Yirmeyah's query make to us, since it only applied upon entry into Israel and is no longer relevant in practice? Why does the Talmud mention it? The Rosh answers that it "can" be relevant in future generations: If a Rabbinical Court (Beis Din) ever enacts a decree prohibiting a certain food, those who already possessed that food before the Sages enacted their decree may still be permitted to consume what they already owned when it was still permitted.
Using these words of the Rosh, Rabbi Yossel Charif engaged in deep Talmudic debate with the "Iron Head" until the latter conceded that the Rebbe could not be forbidden from using his Esrog, which he had owned beforehand. As soon as Rabbi Yossel returned, the Chozeh rejoiced greatly and exclaimed, "Yosef, son of Leitza, you have illuminated our eyes!" They sat down to the pre-Yom Kippur meal with immense joy. From then on, Rabbi Yossel held great prestige with the Chozeh and would always sit among the foremost at his table.