R. Jonathan ben Nathan Nata Eibeschutz (1690/95–1764) was a child prodigy. He studied in Poland, Moravia, and Prague. In his youth, after the death of his father, he studied in Prossnitz under R. Meir Eisenstadt and R. Eliezer ha-Levi Ettinger, his uncle, and in Vienna under R. Samson Wertheimer. He married the daughter of Isaac Spira, the av bet din of Bunzlau. After traveling for some time he settled in Prague in 1715, and in time became head of the yeshivah and a famous preacher. When he was in Prague he had many contacts with priests and the intelligentsia, debating religious topics and matters of faith with them. He became friendly with Cardinal Hassebauer and also discussed religious questions with him. Through the help of the cardinal, R. Eibeschutz received permission to print the Talmud with the omission of all passages contradicting the principles of Christianity. Aroused to anger by this, R. David Oppenheim and the rabbis of Frankfort had the license to print revoked.

The people of Prague held R. Eibeschutz in high esteem and he was considered second only to David Oppenheim. In 1725 he was among the Prague rabbis who excommunicated the Shabbatean sect. After the death of R. David Oppenheim (1736), he was appointed dayyan of Prague. Elected rabbi of Metz in 1741, he subsequently became rabbi of the “Three Communities,” Altona, Hamburg, and Wandsbek (1750). Both in Metz and in Altona he had many disciples and was considered a great preacher. His position in the Three Communities, however, was undermined when the dispute broke out concerning his suspected leanings toward Shabbateanism. This controversy accompanied R. Eibeschutz throughout his life, and the quarrel had repercussions in every community from Holland to Poland. His main opponent was R. Jacob Emden, also a famous talmudist and his rival in the candidature to the rabbinate of the Three Communities. The quarrel developed into a great public dispute which divided the rabbis of the day. While most of the German rabbis opposed R. Eibeschutz, his support came from the rabbis of Poland and Moravia. A fruitless attempt at mediation was made by R. Ezekiel Landau, rabbi of Prague. Most of R. Eibeschutz ' own community was loyal to him and confidently accepted his refutation of the charges made by his opponent, but dissension reached such a pitch that both sides appealed to the authorities in Hamburg and the government of Denmark for a judicial ruling. The king favored R. Eibeschutz and ordered new elections, which resulted in his reappointment. Yet the literary polemic continued, even prompting several Christian scholars to participate, some of whom, thinking that R. Eibeschutz was a secret Christian, came to his defense Scholarly historical research has advanced three views concerning Eybeschuetz' relationship with Shabbateanism: that he was never a Shabbatean and that suspicions on this score were completely unfounded (Zinz, Mortimer, Cohen, Klemperer); that he was a Shabbatean in his youth but turned his back on the sect around the time of the herem of 1725 (Bernhard Baer, Saul Pinhas Rabinowitz); that he was a crypto-Shabbatean from the time he studied in Prossnitz and Prague until the end of his life (Graetz, David Kahana, Scholem, Perlmutter).

The essay on Adar deals with those instances when the Jewish calendar has a leap year and a second Adar is added.

קובץ מאמרים. רובם בגרמנית. 8 עמ', בעברית: "תשובה בענין שני אדרים בשנים המעוברות", מאת ר' יצחק יעקב ('בלא"א... מוהר"ן') קרימקה. 72 ,4 עמ' (נדפסו משמאל לימין) ובהם שני מאמרים בגרמנית, מאת ד"ר יעקב כהן (אודות ר' יהונתן אייבשיץ) וד"ר מאכס לאנדסברג.