LEEUW, JACOB BEN ḤAYYIM (Heymann) DE (1811–1883), Dutch talmudist. De Leeuw was born in Leiden, but also resided for some time in 's Hertogenbosch. In 1874 he went to Amsterdam, where he taught in the bet midrash Eẓ Ḥayyim. He was the author of expositions and novellae on various themes in tractate Ketubbot which were entitled Shoshannat Ya'akov (1848); Peri Eẓ Ḥayyim (1852), with additional notes (1853); Mishkenot ha-Ro'im (1854); Nahalat Ya'akov (1857), in the introduction to which he took issue with Phinehas ha-Levi Horowitz, author of the Hafla'ah, on the subject of whether money may be extracted from its possessor by a majority decision; and Ḥelek Ya'akov (1858). He also wrote Aḥuzzat Mere'im (1879), novellae on tractate Beẓah, and Beit Ya'akov (1880), on the first seven chapters of Ḥullin.