||Collected writings of the holy Maggid of of Mezhirech and his students, from the years 1761 through 1788, with commentary and annotations from the editor, R. Joel Diskin ben Menahem Nahum. Iggeret Kodesh begins with a word to the reader from R. Diskon, a brief biography of the Maggid of of Mezhirech, R. Dov Baer (The Maggid) of Mezhirech and the letters. The forty four correspondence included here are to and from such giants of Hassidut as R. Phinehas Shapiro of Korets (1726–1791), R. Aaron ben Jacob, of Karlin (1736–1772), R. Meshulam Zusya of Annopol (d. 1800), R. Leib ben Sarah, and others.
R. Dov Baer (The Maggid) of Mezhirech (d. 1772) was one of the earliest and most important leaders of Hasidism. As a youth, R. Dov Baer received a traditional religious education in the yeshivah of R. Jacob Joshua Falk, author of Penei Yehoshu'a. He taught in Torchin and later became preacher in Korets and Rovno. Subsequently he moved to Mezhirech (Mezhirichi) in Volhynia, which became the center of the hasidic movement, and toward the end of his life he moved to Annopol (Hanipol). An erudite talmudic scholar, R. Dov Baer also made a profound study of Kabbalah, adopting the system of Lurianic Kabbalah (originated by Isaac Luria) and an ascetic way of life. The mortifications to which he subjected himself eventually made him ill; he contracted a disease which affected his legs and he became bedridden. Tradition relates that he sought a cure from Israel ben Eliezer (the Ba'al Shem Tov), the originator of modern Hasidism, whose reputation as a healer was widespread, and Dov Baer became one of his foremost disciples.
After the death of the Ba'al Shem Tov in 1760, Dov Baer was recognized as his successor to leadership of the movement although opposed by R. Jacob Joseph of Polonnoye, the more senior disciple. The authority of R. Dov Baer as the main proponent of Hasidism was apparently only recognized in 1766, and even then there were a few notable exceptions such as R. Phinehas of Korets. Unlike his predecessor, Dov Baer was not a man of the people, and his illness made it difficult for him to associate with his disciples. He possessed charismatic qualities, however, and was an eloquent preacher and teacher. Solomon Maimon, who visited R. Dov Baer during his youth, expressed great admiration for his spiritual endowments. R. Dov Baer was highly esteemed by his disciples, who not only derived spiritual sustenance from his teachings and utterances but also divined an inner significance in his daily life and actions. Thus, R. Aryeh Leib Sarahs is said to have visited Dov Baer in order "to see how he put on his shoes and tied his shoelaces."