At the early age of twenty-five Tzahalon was requested by Samuel Yafeh, a rabbi of Constantinople, to decide a difficult and complicated problem which had been referred to himself and he corresponded with most of the authorities of his time, one of his chief antagonists being Moses Galante (the Elder). Although a Sephardi, Tzahalon rendered a decision in favor of an Ashkenazic congregation in a controversy which arose between the Sephardim and Ashkenazim at Jerusalem, and in his love of truth he did not spare even his teacher, Joseph Caro, declaring that the Shulchan Aruch was written for children and laymen. Tzahalon was the author of a commentary on the Book of Esther, entitled Lekach Tov (Safed, 1577). He was the author of responsa and novellæ which were published with a preface by his grandson Yom-Tov (Venice, 1694), and he mentions also a second part, of which nothing more is known. He likewise wrote a commentary on the Abot de-Rabbi Natan, entitled Magen Avot, which is still extant in manuscript. In his preface to this latter work Tzahalon terms himself Yom-Tov ben Moses ha-Sefardi, whence it is clear that the family came originally from Spain, although it is not known when it emigrated or where Tzahalon was born.
---- Jewish Encyclopedia bibliography: Giovanni Bernardo De Rossi, Dizionario, s.v.; Graziadio Nepi-Mordecai Ghirondi, Toledot Gedole Yisrael, p. 206; Dukes, in Orient, Lit. ix. 346; Moritz Steinschneider, Cat. Bodl. col. 1414.