Asahel Grant, an American physician, was of the opinion also that the Yezidis, or devil-worshipers, of Mesopotamia were descended from the Ten Tribes, as they observed the rite of circumcision, offered sacrifices, including that of the paschal lamb on the 24th of Nisan, and also abstained from forbidden food (ib. pp. 363-372).

In 1835 Asahel Grant was appointed by the American Board of Foreign Missions to pursue his calling among the Nestorians of Mesopotamia. He found among them a tradition that they were descendants of the Lost Ten Tribes, a tradition which had already been gathered by Smith and White during their earlier mission ("Researches in Armenia," vol. ii.). He found also among the Jews of the neighborhood of Urumiah recognition of this tradition, which he considered to be confirmed by the following facts: they dwelt in the neighborhood to which the Israelites were originally deported, while Josephus declared that the Ten Tribes lived beyond the Euphrates up to his time ("Ant." xi. 5, § 3), and his statement is confirmed by Jerome ("Opera," vi. 780); their language is a branch of the Aramaic; they still offer sacrifices and first-fruits like the ancient Israelites, and they prepare for the Sabbath on the preceding evening; they have Jewish names and Jewish features. Other similarities of custom are recorded by Grant ("The Nestorians, or the Lost Tribes," New York, 1845).