ACOSTA, ISAAC (Yhsak ; d. 1728), French Sephardi rabbi. Probably a native of Amsterdam, Acosta became ḥazzan of the Jewish community of Peyrehorade, near Bayonne, formed by Marrano fugitives from the Iberian Peninsula. His Historia Sacra Real (1691), dedicated to the wardens of the community, is one of the earliest manifestations of Judaism in this place. Later (apparently after an interlude in Biarritz) he succeeded R. Ḥayyim de Mercado as ḥakham at Bayonne, where he composed his handbook for the administration of the last rites to the dying, Vía de Salvación (1709; reprinted by M. Kaplan, Bayonne, 1874), and his major work, Conjeturas Sagradas (Leyden, 1722), a commentary in Spanish on the Early Prophets, based on the classical Hebrew commentators and the Midrash.
Kayserling, Bibl, 8 (and Da Silva Rosa's additions, 4); M. Schwab, Inscriptions Hébraïques de la France (1904), 375–7; Gross, Gal Jud, 93; Loeb, in: rej, 22 (1891), 111.