||Nidhai Israel with the "muga" inscription (twice) by the Hafez Hayyim. The Hafez Hayyim personally checked each volume for completeness and inscribed "muga" on the front fly when complete. R. Israel Meir ha-Kohen Kagan (known as Hafez Hayyim; 1838–1933), one of the most saintly figures in modern Judaism. Of humble origin, he was taught until the age of ten by his parents and then went to Vilna where he continued his studies. He did not particularly distinguish himself as a student; nevertheless, he later towered above all his contemporaries in his qualities of religious leadership. His surname Poupko is hardly known, nor is he referred to by his own name, but he became universally known as Hafez Hayyim, after the title of his first work. His personality, his piety, his humility of conduct, his integrity of thought and action, together with his books, exercised a tremendous influence on religious leaders, and fascinated the masses, to whom he became the admired master and leader. Hundreds of sayings full of practical wisdom are attributed to him, and hundreds of stories both factual and legendary, all rich in morals, are reported about his life.
He refused to make the rabbinate his calling, and after his marriage in Radun subsisted on a small grocery store which his wife managed and for which he did the bookkeeping. He also did his own "bookkeeping," maintaining a daily record of his own deeds to assure himself no wrong had been perpetrated by him nor any time wasted. He spent his time either learning Torah or disseminating its knowledge among others, particularly the more simple folk, whom he always encouraged in matters of learning, observance, and faith. The Hafez Hayyim did not intend to establish a yeshivah. So many students, however, flocked to him that by 1869 his home had become known as "the Radun yeshivah" or as "the Hafez Hayyim yeshiva." Forty-five years later, the yeshiva moved to a big building of its own and R. Naphtali Trup was appointed its head. For many years it was the Hafez Hayyim's responsibility to provide for the students, a task in which he was later assisted by his three sons-in-law, leaving him more time for writing, publishing, and distributing his books. When he was 35 he published anonymously in Vilna (1873) his first book, Hafez Hayyim, devoted entirely to an exposition of the primary importance of the laws of slander, gossip, and tale bearing. Throughout his life, he laid great emphasis on the careful observance of these laws, so generally neglected in spite of the fact that their transgression involves the violation of numerous prohibitions. In 1879 he published another book on the same subject and a third in 1925. He even composed a special prayer to be recited every morning asking for protection from the sins of slander and gossip. His best-known and most widely studied work is his six-volume Mishnah Berurah (1894–1907), a comprehensive commentary on Shulhan Arukh, Orah Hayyim which has been accepted as an indispensable reference book on practical everyday halakhic matters.
The Hafez Hayyim did not publish his books for academic purposes, but rather produced them wherever he saw a need to strengthen some aspect of Jewish life, sometimes intervening in person to reinforce his teaching. Among the 21 books which he published, mention should be made of Ahavat Hesed (1888) on various types of charity; Mahaneh Yisrael (1881), a code of practical laws for Jewish soldiers (he also endeavored to ensure that when stationed near Jewish communities kosher food was provided for them); Niddehei Yisrael (1894) to encourage Jews who had emigrated to the West to maintain their religious loyalties; and a variety of books on the observance of the dietary laws, laws of family purity, and the obligation of Torah study. Since he hoped for and believed in the imminent coming of the Messiah, he emphasized the study of the laws of sacrifices and worship in the Temple and other related subjects. Throughout his life, the Hafez Hayyim traveled extensively to muster support for many Jewish causes. He was one of the founders of the Agudat Israel and was one of its spiritual leaders. He was chosen to open the First World Convention of Agudat Israel (1912). The Hafez Hayyim's help enabled the many European yeshivot to survive the critical financial problems of the interwar period. Under his aegis, the Va'ad ha-Yeshivot (committee on behalf of yeshivot) was organized and it successfully raised the necessary funds for these schools. After his death, his name was perpetuated by many yeshivot and religious institutions throughout the world which were called Hafez Hayyim.