ADAH (ā'da, Heb. ‘ādhâh, ornament)
ADAH ā’ də (עָדָ֔ה, ornament, adornment or beauty). 1. The first of Lamech’s two wives to whom Lamech recited his poem of self-exultation. Adah was the mother of Jabal and Jubal (Gen 4:19-21).
2. The first mentioned wife of Esau, a daughter of Elon the Hitt. (Gen 36:2-16). In Genesis 26:34 Bashemath (RSV BASEMATH), mentioned in Genesis 36:3 as Esau’s third wife, the daughter of Ishmael, is said to be the daughter of Elon the Hitt. It seems unlikely that Esau married two daughters of Elon, one of whom had the same name as another of his wives. The data for the solution of this question is not available. Adah was the mother of Eliphaz (Gen 36:10) whose sons are called the sons of Adah (36:12, 16). The marriage of Esau and Adah introduced Canaanitish blood and influence into Israelitish life.
International Standard Bible Encyclopedia (1915)
(1) One of the two wives of Lamech the descendant of Cain (Ge 4:19,20,23). The narrative in Ge assigns to her two sons, Jabal the "father" of tent-dwelling people, and Jubal the "father" of all such as handle the harp and pipe." Josephus says that Lamech had 77 sons by Ada and Zillah (Ant., I, ii, 2).
(2) According to Ge 36:2,4,10,12,16, the Hittite wife of Esau, daughter of Elon, and mother of Eliphaz. In this chapter Esau’s other wives are Oholibamah, a Hivite, and Basemath the daughter of Ishmael. The names are differently given elsewhere (Ge 26:34; 28:9). Basemath is said to be the daughter of Elon. The daughter of Ishmael is called Mahalath. In place of Oholibamah the Hivite we find Judith the daughter of Beeri the Hittite. Data are lacking for the solution of the problem.
Willis J. Beecher