In the case of Boaz and Ruth the evil yetzer seemed to appear within a sexual context. This list in Sifre Deut., however, shows that the picture is more complicated. The evil yetzer draws one to all possible sins: it draws Boaz to intercourse just as it draws David to murder, and Abraham and Elisha to theft. Other Tannaitic sources clearly confirm this conclusion: the yetzer appears in various contexts in Tannaitic literature, none of which (except this homily about Boaz) is sexual in nature. It appears as creating doubleness in one’s heart, thus preventing the singleness-of-heart needed for religious worship (mBer. 9:5; Sifra Shemini 8); It is presented as the source of anger (t. B.Q. 9:31) or even as anger itself (mAvot 4:1); It prevents men from studying Torah (Sifre Num. 119) and from observing the commandments (Sifre Deut. 43).
Ishay Rosen-Zvi, “Sexualising the Evil Inclination: Rabbinic ‘Yetzer’ and Modern Scholarship,” Journal of Jewish Studies 60, No. 2 (Autumn 2009), 267