URIM AND THUMMIM. - Mysterious objects used in ancient Israel to cast the sacred lots (I Sam. 28:6). The most probable meaning of the two names is "light" and "integrity," but it remains doubtful to what the two names referred (the guilt or innocence of an individual? cf. I Sam. 14:41: Septuagint).
They were kept in a small pouch hanging from the breast of the high priest, to whom alone their use belonged (Ex. 28:30; Lev. 8:8; Num. 27:21; Deut. 33:8). They were considered part of the priestly garment, the ephod (v.), indeed implicitly understood under that latter name, although never explicitly mentioned with it (I Sam. 14:18, critical text; 23:9; 30:7). Their use, attested several times in the time of Saul and David, disappears afterward, perhaps supplanted by prophetism; in the time of Ezra there is only the hope that God will raise up a priest who knows how to use them (Ezra 2:63). How the responses were obtained by means of the 'ä. and t. is stated only in I Sam. 14:41, Septuagint (a doubtful text, which is missing from the Masoretic text). Since the author of a guilt during a military campaign was unknown, Saul placed himself and his son Jonathan on one side, the army on the other, and said: "If this iniquity is in me or in my son, O Lord, God of Israel, give the 'ä.; if instead it is in Israel your people, give the t."; the lot fell on Jonathan and Saul; the test having been repeated between father and son, the lot designated Jonathan. The episode suggests, apart from the fantastic interpretations of late Judaism, that the two objects were two small stones, differing in material, color, and form, one called 'ä., the other t.; the high priest mixed them in the pouch and drew one out, to which, by prior designation, the response was entrusted.