In Europe it was the custom to fatten up geese in the months preceding Passover, since many families refrained from using any oil other than goose fat. For six to eight weeks the geese would be fed a full bucket of corn twice a day, so that by the time the holiday arrived they would be so huge they could barely waddle.
Two religious giants of the day, the Chasam Sofer (Rabbi Moshe Sofer) and the Yismach Moshe (Rabbi Moshe Teitelbaum) differed in their rulings as to whether the practice of force-feeding rendered the geese treife. The question revolved around whether or not the sharp corn grains which were forced down the throats of the birds would damage the esophagus, thus making the birds treife (i.e., unable to live another year). The Chasam Sofer held that the esophagus would not necessarily be damaged, and so he ruled the practice permissible. (Of course, the geese had to be carefully checked before being consumed to prove that they were kosher by the process described later.) His contemporary, the Yismach Moshe felt that since the corn kernels were sharp, the likelihood was that the birds would be rendered treife by the force feedings. He ruled that geese fed in this manner would not be permissible.
The two corresponded back and forth, each presenting learned arguments to prove his point, their dispute purely "for the sake of heaven." Finally, the Chasam Sofer suggested that instead of theorizing, they should put their rulings to a practical test. Each was to take ten geese and fattened them up. Then, they would slaughter them, fill the esophagi with air and float them in a full tub of water. If the esophagus was damaged air bubbles would escape into the water, thus proving that the bird was treife. If no bubbles were seen, the bird would be kosher.
When the birds were duly fattened and slaughtered, an amazing thing took place. All the birds from the household of the Chasam Sofer proved to be kosher, whereas all the birds of the Yismach Moshe tested treife.
So it was seen that the legal rulings of these two great giants dominated the physical reality, proving the axiom that the rulings of true halachic authorities determine the actual reality of a physical situation.
Another story is told which illustrates the same point. There lived in Europe in the last century a well-known Chasidic rabbi who was rebbe to tens of thousands of chasidim. He was known as the Zidochover Maggid. One Friday as he sat and learned Torah with a group of his disciples, a woman entered his study carrying a chicken which she wished to prepare for the Shabbat meal. However, there was a question on the kashrut of the bird, so she had brought it to the Rabbi to ask if it was permissible. Now, on the face of it, the chicken had lesions on its lung which would normally indicate that it was treife, but to the astonishment of his students, the Rebbe spent hours studying many texts in an attempt to find an opinion which would permit the chicken. It was incomprehensible to them just why the Rebbe would go to such lengths when he could just as easily give the woman a ruble to buy another chicken. After hours of study the Rebbe stood up and pronounced the chicken kosher! The Rebbe's disciples couldn't believe their ears, but he had labored and succeeded in finding a way to rule the chicken permissible. The happy woman went home to prepare her Shabbat meal, and the scholars resumed their study.
Soon after she left another woman entered the hall in a state of hysteria. "Rebbe, Rebbe!" she screamed, as she fainted to the floor. When she was revived she resumed her wailing, crying, "Rebbe, you must help me, my husband, the doctors have given up hope!" Again the poor woman fainted and had to be revived. The Rebbe stood by her side and said, "Tell me please, what is the exact nature of your husband's ailment?"
She replied that he had serious lesions on his lungs. When he heard that, the Rebbe comforted her saying, "I just ruled that this type of malady is kosher. Go home and don't worry; your husband will live for many years." And this, in fact, is what happened. Only then did the students understand that through his ruach hakodesh (spiritual insight) the Rebbe had known that he would need that halachic ruling to help a fellow Jew. Through his pronouncement which allowed the chicken to be used he also, so to speak, negated the fatal effects of the same illness on a fellow Jew.
