In addition, Elijah condemns Ahaziah for seeking healing apart from Yahweh (2 Kings 1:2–4), and Jeremiah scoffs at medicine’s efficacy (Jeremiah 8:22, 17:5, 14, 46:11, 51:8–9). All approved acts of healing involve either Yahweh or his priests and prophets (Genesis 20:7, 17; Exodus 23:25–26; Numbers 12:13; 1 Kings 13:6, 17:17–24; 2 Kings 4:8–41, 5, 13:21, 20:1–7). In contrast, we have a single oblique but neutral reference to medical expenses in Exodus 21:19. The earliest positive reference to healing in Jewish literature is Ben Sira 38:1–15 (second century B.C.E.). Starting in the Middle Ages and until modern times, however, Jews have traditionally specialized in medicine. See John M. Efron, Medicine and the German Jews (New Haven: Yale Univ. Press, 2001).