R. Dov Baer (1773–1827), the eldest son of R. Shneur Zalman, became after his father's death in 1813 the leader of the majority of his father's Hasidim. He settled in the little town of Lubavich, which became the center of Habad. Under R. Dov Baer's leadership, the Habad approach was strengthened and deepened. His blend of intellect and mysticism is expressed in his clear and profound commentaries on his father's works. He was a prolific writer and wrote many works, the majority being explanations of diverse subjects, among them Kunteres ha-Hitpa'alut (1876; Tractate on Ecstasy, 1963), according to his systematized Habad Hasidism. At the same time he supported the idea of productivization in Jewish economy, and encouraged his Hasidim to take up manual occupations. He also persuaded all the Habad Hasidim in Erez Israel to settle in Hebron (1820) which became the Habad center there. R. Dov Baer was imprisoned for a time because of accusations against him by an informer, but was released on the 10th of Kislev, which is celebrated as a minor holiday among Habad Hasidim. He passed on in Nezhin in Ukraine.